Skip to content

Commit b4bcb24

Browse files
yanglbmeyanglbme
authored
feat: add solutions to lc problems: No.1063,1064 (doocs#1541)
* No.1063.Number of Valid Subarrays * No.1064.Fixed Point
1 parent d66a5fe commit b4bcb24

File tree

11 files changed

+271
-62
lines changed

11 files changed

+271
-62
lines changed

‎solution/1000-1099/1063.Number of Valid Subarrays/README.md

Lines changed: 97 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -83,6 +83,20 @@ class Solution:
8383
return sum(j - i for i, j in enumerate(right))
8484
```
8585

86+
```python
87+
class Solution:
88+
def validSubarrays(self, nums: List[int]) -> int:
89+
n = len(nums)
90+
stk = []
91+
ans = 0
92+
for i in range(n - 1, -1, -1):
93+
while stk and nums[stk[-1]] >= nums[i]:
94+
stk.pop()
95+
ans += (stk[-1] if stk else n) - i
96+
stk.append(i)
97+
return ans
98+
```
99+
86100
### **Java**
87101

88102
<!-- 这里可写当前语言的特殊实现逻辑 -->
@@ -112,6 +126,25 @@ class Solution {
112126
}
113127
```
114128

129+
```java
130+
class Solution {
131+
public int validSubarrays(int[] nums) {
132+
int n = nums.length;
133+
Deque<Integer> stk = new ArrayDeque<>();
134+
int ans = 0;
135+
for (int i = n - 1; i >= 0; --i) {
136+
while (!stk.isEmpty() && nums[stk.peek()] >= nums[i]) {
137+
stk.pop();
138+
}
139+
ans += (stk.isEmpty() ? n : stk.peek()) - i;
140+
141+
stk.push(i);
142+
}
143+
return ans;
144+
}
145+
}
146+
```
147+
115148
### **C++**
116149

117150
```cpp
@@ -139,6 +172,25 @@ public:
139172
};
140173
```
141174
175+
```cpp
176+
class Solution {
177+
public:
178+
int validSubarrays(vector<int>& nums) {
179+
int n = nums.size();
180+
stack<int> stk;
181+
int ans = 0;
182+
for (int i = n - 1; ~i; --i) {
183+
while (stk.size() && nums[stk.top()] >= nums[i]) {
184+
stk.pop();
185+
}
186+
ans += (stk.size() ? stk.top() : n) - i;
187+
stk.push(i);
188+
}
189+
return ans;
190+
}
191+
};
192+
```
193+
142194
### **Go**
143195

144196
```go
@@ -165,32 +217,66 @@ func validSubarrays(nums []int) (ans int) {
165217
}
166218
```
167219

168-
### **TypeScript**
169-
170-
```ts
220+
```go
171221
func validSubarrays(nums []int) (ans int) {
172222
n := len(nums)
173-
right := make([]int, n)
174-
for i := range right {
175-
right[i] = n
176-
}
177223
stk := []int{}
178224
for i := n - 1; i >= 0; i-- {
179225
for len(stk) > 0 && nums[stk[len(stk)-1]] >= nums[i] {
180226
stk = stk[:len(stk)-1]
181227
}
228+
ans -= i
182229
if len(stk) > 0 {
183-
right[i] = stk[len(stk)-1]
230+
ans += stk[len(stk)-1]
231+
} else {
232+
ans += n
184233
}
185234
stk = append(stk, i)
186235
}
187-
for i, j := range right {
188-
ans += j - i
189-
}
190236
return
191237
}
192238
```
193239

240+
### **TypeScript**
241+
242+
```ts
243+
function validSubarrays(nums: number[]): number {
244+
const n = nums.length;
245+
const right: number[] = Array(n).fill(n);
246+
const stk: number[] = [];
247+
for (let i = n - 1; ~i; --i) {
248+
while (stk.length && nums[stk.at(-1)] >= nums[i]) {
249+
stk.pop();
250+
}
251+
if (stk.length) {
252+
right[i] = stk.at(-1)!;
253+
}
254+
stk.push(i);
255+
}
256+
let ans = 0;
257+
for (let i = 0; i < n; ++i) {
258+
ans += right[i] - i;
259+
}
260+
return ans;
261+
}
262+
```
263+
264+
```ts
265+
function validSubarrays(nums: number[]): number {
266+
const n = nums.length;
267+
const stk: number[] = [];
268+
let ans = 0;
269+
for (let i = n - 1; ~i; --i) {
270+
while (stk.length && nums[stk.at(-1)!] >= nums[i]) {
271+
stk.pop();
272+
}
273+
ans += (stk.at(-1) ?? n) - i;
274+
stk.push(i);
275+
}
276+
return ans;
277+
}
278+
```
279+
194280
### **...**
195281

196282
```

‎solution/1000-1099/1063.Number of Valid Subarrays/README_EN.md

Lines changed: 97 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -62,6 +62,20 @@ class Solution:
6262
return sum(j - i for i, j in enumerate(right))
6363
```
6464

65+
```python
66+
class Solution:
67+
def validSubarrays(self, nums: List[int]) -> int:
68+
n = len(nums)
69+
stk = []
70+
ans = 0
71+
for i in range(n - 1, -1, -1):
72+
while stk and nums[stk[-1]] >= nums[i]:
73+
stk.pop()
74+
ans += (stk[-1] if stk else n) - i
75+
stk.append(i)
76+
return ans
77+
```
78+
6579
### **Java**
6680

6781
```java
@@ -89,6 +103,25 @@ class Solution {
89103
}
90104
```
91105

106+
```java
107+
class Solution {
108+
public int validSubarrays(int[] nums) {
109+
int n = nums.length;
110+
Deque<Integer> stk = new ArrayDeque<>();
111+
int ans = 0;
112+
for (int i = n - 1; i >= 0; --i) {
113+
while (!stk.isEmpty() && nums[stk.peek()] >= nums[i]) {
114+
stk.pop();
115+
}
116+
ans += (stk.isEmpty() ? n : stk.peek()) - i;
117+
118+
stk.push(i);
119+
}
120+
return ans;
121+
}
122+
}
123+
```
124+
92125
### **C++**
93126

94127
```cpp
@@ -116,6 +149,25 @@ public:
116149
};
117150
```
118151
152+
```cpp
153+
class Solution {
154+
public:
155+
int validSubarrays(vector<int>& nums) {
156+
int n = nums.size();
157+
stack<int> stk;
158+
int ans = 0;
159+
for (int i = n - 1; ~i; --i) {
160+
while (stk.size() && nums[stk.top()] >= nums[i]) {
161+
stk.pop();
162+
}
163+
ans += (stk.size() ? stk.top() : n) - i;
164+
stk.push(i);
165+
}
166+
return ans;
167+
}
168+
};
169+
```
170+
119171
### **Go**
120172

121173
```go
@@ -142,32 +194,66 @@ func validSubarrays(nums []int) (ans int) {
142194
}
143195
```
144196

145-
### **TypeScript**
146-
147-
```ts
197+
```go
148198
func validSubarrays(nums []int) (ans int) {
149199
n := len(nums)
150-
right := make([]int, n)
151-
for i := range right {
152-
right[i] = n
153-
}
154200
stk := []int{}
155201
for i := n - 1; i >= 0; i-- {
156202
for len(stk) > 0 && nums[stk[len(stk)-1]] >= nums[i] {
157203
stk = stk[:len(stk)-1]
158204
}
205+
ans -= i
159206
if len(stk) > 0 {
160-
right[i] = stk[len(stk)-1]
207+
ans += stk[len(stk)-1]
208+
} else {
209+
ans += n
161210
}
162211
stk = append(stk, i)
163212
}
164-
for i, j := range right {
165-
ans += j - i
166-
}
167213
return
168214
}
169215
```
170216

217+
### **TypeScript**
218+
219+
```ts
220+
function validSubarrays(nums: number[]): number {
221+
const n = nums.length;
222+
const right: number[] = Array(n).fill(n);
223+
const stk: number[] = [];
224+
for (let i = n - 1; ~i; --i) {
225+
while (stk.length && nums[stk.at(-1)] >= nums[i]) {
226+
stk.pop();
227+
}
228+
if (stk.length) {
229+
right[i] = stk.at(-1)!;
230+
}
231+
stk.push(i);
232+
}
233+
let ans = 0;
234+
for (let i = 0; i < n; ++i) {
235+
ans += right[i] - i;
236+
}
237+
return ans;
238+
}
239+
```
240+
241+
```ts
242+
function validSubarrays(nums: number[]): number {
243+
const n = nums.length;
244+
const stk: number[] = [];
245+
let ans = 0;
246+
for (let i = n - 1; ~i; --i) {
247+
while (stk.length && nums[stk.at(-1)!] >= nums[i]) {
248+
stk.pop();
249+
}
250+
ans += (stk.at(-1) ?? n) - i;
251+
stk.push(i);
252+
}
253+
return ans;
254+
}
255+
```
256+
171257
### **...**
172258

173259
```

‎solution/1000-1099/1063.Number of Valid Subarrays/Solution.cpp

Lines changed: 2 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -2,21 +2,15 @@ class Solution {
22
public:
33
int validSubarrays(vector<int>& nums) {
44
int n = nums.size();
5-
vector<int> right(n, n);
65
stack<int> stk;
6+
int ans = 0;
77
for (int i = n - 1; ~i; --i) {
88
while (stk.size() && nums[stk.top()] >= nums[i]) {
99
stk.pop();
1010
}
11-
if (stk.size()) {
12-
right[i] = stk.top();
13-
}
11+
ans += (stk.size() ? stk.top() : n) - i;
1412
stk.push(i);
1513
}
16-
int ans = 0;
17-
for (int i = 0; i < n; ++i) {
18-
ans += right[i] - i;
19-
}
2014
return ans;
2115
}
2216
};

‎solution/1000-1099/1063.Number of Valid Subarrays/Solution.go

Lines changed: 4 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -1,21 +1,17 @@
11
func validSubarrays(nums []int) (ans int) {
22
n := len(nums)
3-
right := make([]int, n)
4-
for i := range right {
5-
right[i] = n
6-
}
73
stk := []int{}
84
for i := n - 1; i >= 0; i-- {
95
for len(stk) > 0 && nums[stk[len(stk)-1]] >= nums[i] {
106
stk = stk[:len(stk)-1]
117
}
8+
ans -= i
129
if len(stk) > 0 {
13-
right[i] = stk[len(stk)-1]
10+
ans += stk[len(stk)-1]
11+
} else {
12+
ans += n
1413
}
1514
stk = append(stk, i)
1615
}
17-
for i, j := range right {
18-
ans += j - i
19-
}
2016
return
2117
}

‎solution/1000-1099/1063.Number of Valid Subarrays/Solution.java

Lines changed: 3 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -1,22 +1,16 @@
11
class Solution {
22
public int validSubarrays(int[] nums) {
33
int n = nums.length;
4-
int[] right = new int[n];
5-
Arrays.fill(right, n);
64
Deque<Integer> stk = new ArrayDeque<>();
5+
int ans = 0;
76
for (int i = n - 1; i >= 0; --i) {
87
while (!stk.isEmpty() && nums[stk.peek()] >= nums[i]) {
98
stk.pop();
109
}
11-
if (!stk.isEmpty()) {
12-
right[i] = stk.peek();
13-
}
10+
ans += (stk.isEmpty() ? n : stk.peek()) - i;
11+
1412
stk.push(i);
1513
}
16-
int ans = 0;
17-
for (int i = 0; i < n; ++i) {
18-
ans += right[i] - i;
19-
}
2014
return ans;
2115
}
2216
}

‎solution/1000-1099/1063.Number of Valid Subarrays/Solution.py

Lines changed: 3 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -1,12 +1,11 @@
11
class Solution:
22
def validSubarrays(self, nums: List[int]) -> int:
33
n = len(nums)
4-
right = [n] * n
54
stk = []
5+
ans = 0
66
for i in range(n - 1, -1, -1):
77
while stk and nums[stk[-1]] >= nums[i]:
88
stk.pop()
9-
if stk:
10-
right[i] = stk[-1]
9+
ans += (stk[-1] if stk else n) - i
1110
stk.append(i)
12-
return sum(j - i for i, j in enumerate(right))
11+
return ans

0 commit comments

Comments
 (0)