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feat: add solutions to lc problem: No.2222
No.2222.Number of Ways to Select Buildings
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Diff for: ‎solution/2200-2299/2222.Number of Ways to Select Buildings/README.md

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Original file line numberDiff line numberDiff line change
@@ -58,22 +58,117 @@
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<!-- 这里可写通用的实现逻辑 -->
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**方法一：统计 010 和 101 的出现次数**
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有效方案只有两种情况：$010$ 和 $101$。枚举中间数字，累计方案数。
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时间复杂度 $O(n)$，其中 $n$ 表示 $s$ 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 numberOfWays(self, s: str) -> int:
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n = len(s)
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cnt0 = s.count("0")
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cnt1 = n - cnt0
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c0 = c1 = 0
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ans = 0
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for c in s:
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if c == "0":
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ans += c1 * (cnt1 - c1)
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c0 += 1
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else:
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ans += c0 * (cnt0 - c0)
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c1 += 1
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return ans
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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 long numberOfWays(String s) {
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int n = s.length();
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int cnt0 = 0;
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for (char c : s.toCharArray()) {
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if (c == '0') {
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++cnt0;
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}
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}
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int cnt1 = n - cnt0;
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long ans = 0;
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int c0 = 0, c1 = 0;
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for (char c : s.toCharArray()) {
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if (c == '0') {
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ans += c1 * (cnt1 - c1);
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++c0;
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} else {
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ans += c0 * (cnt0 - c0);
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++c1;
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}
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}
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return ans;
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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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long long numberOfWays(string s) {
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int n = s.size();
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int cnt0 = 0;
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for (char& c : s) cnt0 += c == '0';
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int cnt1 = n - cnt0;
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int c0 = 0, c1 = 0;
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long long ans = 0;
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for (char& c : s)
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{
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if (c == '0')
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{
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ans += c1 * (cnt1 - c1);
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++c0;
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}
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else
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{
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ans += c0 * (cnt0 - c0);
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++c1;
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}
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}
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return ans;
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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 numberOfWays(s string) int64 {
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n := len(s)
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cnt0 := strings.Count(s, "0")
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cnt1 := n - cnt0
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c0, c1 := 0, 0
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ans := 0
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for _, c := range s {
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if c == '0' {
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ans += c1 * (cnt1 - c1)
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c0++
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} else {
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ans += c0 * (cnt0 - c0)
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c1++
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}
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}
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return int64(ans)
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}
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```
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### **TypeScript**

Diff for: ‎solution/2200-2299/2222.Number of Ways to Select Buildings/README_EN.md

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@@ -59,13 +59,102 @@ No other selection is valid. Thus, there are 6 total ways.
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### **Python3**
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```python
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class Solution:
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def numberOfWays(self, s: str) -> int:
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n = len(s)
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cnt0 = s.count("0")
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cnt1 = n - cnt0
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c0 = c1 = 0
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ans = 0
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for c in s:
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if c == "0":
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ans += c1 * (cnt1 - c1)
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c0 += 1
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else:
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ans += c0 * (cnt0 - c0)
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c1 += 1
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return ans
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```
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### **Java**
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```java
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class Solution {
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public long numberOfWays(String s) {
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int n = s.length();
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int cnt0 = 0;
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for (char c : s.toCharArray()) {
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if (c == '0') {
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++cnt0;
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}
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}
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int cnt1 = n - cnt0;
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long ans = 0;
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int c0 = 0, c1 = 0;
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for (char c : s.toCharArray()) {
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if (c == '0') {
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ans += c1 * (cnt1 - c1);
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++c0;
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} else {
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ans += c0 * (cnt0 - c0);
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++c1;
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}
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}
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return ans;
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}
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}
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```
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### **C++**
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```cpp
111+
class Solution {
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public:
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long long numberOfWays(string s) {
114+
int n = s.size();
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int cnt0 = 0;
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for (char& c : s) cnt0 += c == '0';
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int cnt1 = n - cnt0;
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int c0 = 0, c1 = 0;
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long long ans = 0;
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for (char& c : s)
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{
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if (c == '0')
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{
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ans += c1 * (cnt1 - c1);
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++c0;
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}
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else
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{
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ans += c0 * (cnt0 - c0);
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++c1;
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}
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}
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return ans;
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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 numberOfWays(s string) int64 {
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n := len(s)
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cnt0 := strings.Count(s, "0")
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cnt1 := n - cnt0
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c0, c1 := 0, 0
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ans := 0
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for _, c := range s {
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if c == '0' {
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ans += c1 * (cnt1 - c1)
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c0++
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} else {
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ans += c0 * (cnt0 - c0)
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c1++
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}
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}
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return int64(ans)
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}
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```
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### **TypeScript**

Diff for: ‎solution/2200-2299/2222.Number of Ways to Select Buildings/Solution.cpp

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,25 @@
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class Solution {
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public:
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long long numberOfWays(string s) {
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int n = s.size();
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int cnt0 = 0;
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for (char& c : s) cnt0 += c == '0';
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int cnt1 = n - cnt0;
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int c0 = 0, c1 = 0;
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long long ans = 0;
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for (char& c : s)
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{
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if (c == '0')
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{
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ans += c1 * (cnt1 - c1);
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++c0;
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}
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else
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{
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ans += c0 * (cnt0 - c0);
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++c1;
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}
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}
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return ans;
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}
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};

Diff for: ‎solution/2200-2299/2222.Number of Ways to Select Buildings/Solution.go

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,17 @@
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func numberOfWays(s string) int64 {
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n := len(s)
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cnt0 := strings.Count(s, "0")
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cnt1 := n - cnt0
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c0, c1 := 0, 0
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ans := 0
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for _, c := range s {
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if c == '0' {
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ans += c1 * (cnt1 - c1)
10+
c0++
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} else {
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ans += c0 * (cnt0 - c0)
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c1++
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}
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}
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return int64(ans)
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}

Diff for: ‎solution/2200-2299/2222.Number of Ways to Select Buildings/Solution.java

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,24 @@
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class Solution {
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public long numberOfWays(String s) {
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int n = s.length();
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int cnt0 = 0;
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for (char c : s.toCharArray()) {
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if (c == '0') {
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++cnt0;
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}
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}
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int cnt1 = n - cnt0;
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long ans = 0;
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int c0 = 0, c1 = 0;
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for (char c : s.toCharArray()) {
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if (c == '0') {
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ans += c1 * (cnt1 - c1);
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++c0;
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} else {
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ans += c0 * (cnt0 - c0);
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++c1;
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}
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}
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return ans;
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}
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}

Diff for: ‎solution/2200-2299/2222.Number of Ways to Select Buildings/Solution.py

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,15 @@
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class Solution:
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def numberOfWays(self, s: str) -> int:
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n = len(s)
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cnt0 = s.count("0")
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cnt1 = n - cnt0
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c0 = c1 = 0
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ans = 0
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for c in s:
9+
if c == "0":
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ans += c1 * (cnt1 - c1)
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c0 += 1
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else:
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ans += c0 * (cnt0 - c0)
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c1 += 1
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return ans

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