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feat: add solutions to lc problem: No.0927
No.0927.Three Equal Parts
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‎solution/0900-0999/0927.Three Equal Parts/README.md

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Original file line numberDiff line numberDiff line change
@@ -57,22 +57,171 @@
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<!-- 这里可写通用的实现逻辑 -->
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**方法一：将 1 的数量三等分**
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将 $1$ 的数量三等分，找到每一部分的第一个 $1$，分别记为 $i$, $j$, $k$。
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然后从 $i$, $j$, $k$ 开始往后同时遍历每一部分，判断三部分对应的值是否相等，是则继续遍历，直至 $k$ 到达 $arr$ 末尾。
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遍历结束时，若 $k=n$，说明满足三等分，返回此时的 $[i-1,j]$ 作为答案。
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时间复杂度 $O(n)$，其中 $n$ 表示 $arr$ 的长度。
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<!-- tabs:start -->
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### **Python3**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```python
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class Solution:
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def threeEqualParts(self, arr: List[int]) -> List[int]:
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def find(cnt):
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s = 0
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for i, v in enumerate(arr):
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s += v
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if s == cnt:
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return i
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return -1
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n = len(arr)
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cnt, mod = divmod(sum(arr), 3)
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if mod:
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return [-1, -1]
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if cnt == 0:
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return [0, n - 1]
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i = find(1)
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j = find(cnt + 1)
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k = find(cnt * 2 + 1)
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while k < n and arr[i] == arr[j] == arr[k]:
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i, j, k = i + 1, j + 1, k + 1
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if k == n:
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return [i - 1, j]
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return [-1, -1]
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```
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### **Java**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```java
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class Solution {
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public int[] threeEqualParts(int[] arr) {
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int n = arr.length;
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int cnt1 = 0;
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for (int v : arr) {
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cnt1 += v;
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}
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int cnt = cnt1 / 3;
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int mod = cnt1 % 3;
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if (mod != 0) {
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return new int[]{-1, -1};
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}
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if (cnt == 0) {
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return new int[]{0, n - 1};
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}
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int i = find(arr, 1);
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int j = find(arr, cnt + 1);
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int k = find(arr, cnt * 2 + 1);
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while (k < n && arr[i] == arr[j] && arr[j] == arr[k]) {
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++i;
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++j;
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++k;
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}
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if (k == n) {
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return new int[]{i - 1, j};
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}
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return new int[]{-1, -1};
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}
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private int find(int[] arr, int cnt) {
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int s = 0;
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for (int i = 0; i < arr.length; ++i) {
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s += arr[i];
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if (s == cnt) {
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return i;
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}
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}
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return -1;
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}
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}
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```
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### **C++**
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```cpp
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class Solution {
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public:
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vector<int> threeEqualParts(vector<int>& arr) {
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int n = arr.size();
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int cnt1 = accumulate(arr.begin(), arr.end(), 0);
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int cnt = cnt1 / 3;
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int mod = cnt1 % 3;
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if (mod) return {-1, -1};
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if (cnt == 0) return {0, n - 1};
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int i = find(arr, 1);
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int j = find(arr, cnt + 1);
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int k = find(arr, cnt * 2 + 1);
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while (k < n && arr[i] == arr[j] && arr[j] == arr[k])
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{
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++i;
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++j;
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++k;
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}
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if (k == n) return {i - 1, j};
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return {-1, -1};
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}
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int find(vector<int>& arr, int cnt) {
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int s = 0;
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for (int i = 0; i < arr.size(); ++i)
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{
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s += arr[i];
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if (s == cnt) return i;
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}
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return -1;
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}
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};
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```
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### **Go**
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```go
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func threeEqualParts(arr []int) []int {
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n := len(arr)
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cnt1 := 0
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for _, v := range arr {
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cnt1 += v
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}
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cnt := cnt1 / 3
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mod := cnt1 % 3
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if mod != 0 {
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return []int{-1, -1}
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}
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if cnt == 0 {
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return []int{0, n - 1}
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}
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find := func(cnt int) int {
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s := 0
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for i, v := range arr {
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s += v
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if s == cnt {
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return i
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}
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}
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return -1
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}
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i, j, k := find(1), find(cnt+1), find(cnt*2+1)
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for k < n && arr[i] == arr[j] && arr[j] == arr[k] {
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i++
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j++
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k++
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}
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if k == n {
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return []int{i - 1, j}
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}
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return []int{-1, -1}
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}
76225
```
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### **...**

‎solution/0900-0999/0927.Three Equal Parts/README_EN.md

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Original file line numberDiff line numberDiff line change
@@ -45,13 +45,152 @@
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### **Python3**
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```python
48-
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class Solution:
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def threeEqualParts(self, arr: List[int]) -> List[int]:
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def find(cnt):
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s = 0
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for i, v in enumerate(arr):
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s += v
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if s == cnt:
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return i
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return -1
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n = len(arr)
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cnt, mod = divmod(sum(arr), 3)
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if mod:
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return [-1, -1]
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if cnt == 0:
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return [0, n - 1]
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i = find(1)
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j = find(cnt + 1)
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k = find(cnt * 2 + 1)
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while k < n and arr[i] == arr[j] == arr[k]:
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i, j, k = i + 1, j + 1, k + 1
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if k == n:
70+
return [i - 1, j]
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return [-1, -1]
4972
```
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### **Java**
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```java
77+
class Solution {
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public int[] threeEqualParts(int[] arr) {
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int n = arr.length;
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int cnt1 = 0;
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for (int v : arr) {
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cnt1 += v;
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}
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int cnt = cnt1 / 3;
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int mod = cnt1 % 3;
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if (mod != 0) {
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return new int[]{-1, -1};
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}
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if (cnt == 0) {
90+
return new int[]{0, n - 1};
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}
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int i = find(arr, 1);
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int j = find(arr, cnt + 1);
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int k = find(arr, cnt * 2 + 1);
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while (k < n && arr[i] == arr[j] && arr[j] == arr[k]) {
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++i;
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++j;
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++k;
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}
100+
if (k == n) {
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return new int[]{i - 1, j};
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}
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return new int[]{-1, -1};
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}
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private int find(int[] arr, int cnt) {
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int s = 0;
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for (int i = 0; i < arr.length; ++i) {
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s += arr[i];
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if (s == cnt) {
111+
return i;
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}
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}
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return -1;
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}
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}
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```
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### **C++**
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```cpp
122+
class Solution {
123+
public:
124+
vector<int> threeEqualParts(vector<int>& arr) {
125+
int n = arr.size();
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int cnt1 = accumulate(arr.begin(), arr.end(), 0);
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int cnt = cnt1 / 3;
128+
int mod = cnt1 % 3;
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if (mod) return {-1, -1};
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if (cnt == 0) return {0, n - 1};
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int i = find(arr, 1);
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int j = find(arr, cnt + 1);
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int k = find(arr, cnt * 2 + 1);
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while (k < n && arr[i] == arr[j] && arr[j] == arr[k])
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{
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++i;
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++j;
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++k;
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}
140+
if (k == n) return {i - 1, j};
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return {-1, -1};
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}
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int find(vector<int>& arr, int cnt) {
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int s = 0;
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for (int i = 0; i < arr.size(); ++i)
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{
148+
s += arr[i];
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if (s == cnt) return i;
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}
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return -1;
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}
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};
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```
54155

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### **Go**
157+
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```go
159+
func threeEqualParts(arr []int) []int {
160+
n := len(arr)
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cnt1 := 0
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for _, v := range arr {
163+
cnt1 += v
164+
}
165+
cnt := cnt1 / 3
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mod := cnt1 % 3
167+
if mod != 0 {
168+
return []int{-1, -1}
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}
170+
if cnt == 0 {
171+
return []int{0, n - 1}
172+
}
173+
find := func(cnt int) int {
174+
s := 0
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for i, v := range arr {
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s += v
177+
if s == cnt {
178+
return i
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}
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}
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return -1
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}
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i, j, k := find(1), find(cnt+1), find(cnt*2+1)
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for k < n && arr[i] == arr[j] && arr[j] == arr[k] {
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i++
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j++
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k++
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}
189+
if k == n {
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return []int{i - 1, j}
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}
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return []int{-1, -1}
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}
55194
```
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57196
### **...**

‎solution/0900-0999/0927.Three Equal Parts/Solution.cpp

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,32 @@
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class Solution {
2+
public:
3+
vector<int> threeEqualParts(vector<int>& arr) {
4+
int n = arr.size();
5+
int cnt1 = accumulate(arr.begin(), arr.end(), 0);
6+
int cnt = cnt1 / 3;
7+
int mod = cnt1 % 3;
8+
if (mod) return {-1, -1};
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if (cnt == 0) return {0, n - 1};
10+
int i = find(arr, 1);
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int j = find(arr, cnt + 1);
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int k = find(arr, cnt * 2 + 1);
13+
while (k < n && arr[i] == arr[j] && arr[j] == arr[k])
14+
{
15+
++i;
16+
++j;
17+
++k;
18+
}
19+
if (k == n) return {i - 1, j};
20+
return {-1, -1};
21+
}
22+
23+
int find(vector<int>& arr, int cnt) {
24+
int s = 0;
25+
for (int i = 0; i < arr.size(); ++i)
26+
{
27+
s += arr[i];
28+
if (s == cnt) return i;
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}
30+
return -1;
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}
32+
};

‎solution/0900-0999/0927.Three Equal Parts/Solution.go

+35
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,35 @@
1+
func threeEqualParts(arr []int) []int {
2+
n := len(arr)
3+
cnt1 := 0
4+
for _, v := range arr {
5+
cnt1 += v
6+
}
7+
cnt := cnt1 / 3
8+
mod := cnt1 % 3
9+
if mod != 0 {
10+
return []int{-1, -1}
11+
}
12+
if cnt == 0 {
13+
return []int{0, n - 1}
14+
}
15+
find := func(cnt int) int {
16+
s := 0
17+
for i, v := range arr {
18+
s += v
19+
if s == cnt {
20+
return i
21+
}
22+
}
23+
return -1
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}
25+
i, j, k := find(1), find(cnt+1), find(cnt*2+1)
26+
for k < n && arr[i] == arr[j] && arr[j] == arr[k] {
27+
i++
28+
j++
29+
k++
30+
}
31+
if k == n {
32+
return []int{i - 1, j}
33+
}
34+
return []int{-1, -1}
35+
}

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