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feat: add solutions to lc problem: No.0209
No.0209.Minimum Size Subarray Sum
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‎solution/0200-0299/0209.Minimum Size Subarray Sum/README.md

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Original file line numberDiff line numberDiff line change
@@ -56,43 +56,41 @@
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<!-- 这里可写通用的实现逻辑 -->
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“前缀和 + 二分查找”，先求出数组的前缀和 `preSum`，然后根据 `preSum[i] - preSum[j] >= target` => `preSum[i] >= preSum[j] + target`，对 `preSum[i]` 进行二分查找，然后更新最小长度即可。时间复杂度 `O(n logn)`。
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**方法一：前缀和 + 二分查找**
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也可以用“滑动窗口”。
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先求出数组的前缀和 `s`，然后根据 `s[j] - s[i] >= target` => `s[j] >= s[i] + target`，找出最小的一个 j，使得 `s[j]` 满足大于等于 `s[i] + target`，然后更新最小长度即可。
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使用指针 left, right 分别表示子数组的开始位置和结束位置，维护变量 sum 表示子数组 `nums[left...right]` 元素之和。初始时 left, right 均指向 0。每一次迭代，将 `nums[right]` 加到 sum，如果此时 `sum >= target`，更新最小长度即可。然后将 sum 减去 `nums[left]`，接着 left 指针右移直至 `sum < target`。每一次迭代最后，将 right 指针右移。时间复杂度 `O(n)`。
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时间复杂度 `O(n logn)`。
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**方法二：滑动窗口**
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使用指针 left, right 分别表示子数组的开始位置和结束位置，维护变量 sum 表示子数组 `nums[left...right]` 元素之和。初始时 left, right 均指向 0。每一次迭代，将 `nums[right]` 加到 sum，如果此时 `sum >= target`，更新最小长度即可。然后将 sum 减去 `nums[left]`，接着 left 指针右移直至 `sum < target`。每一次迭代最后，将 right 指针右移。
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时间复杂度 `O(n)`。
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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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“前缀和 + 二分查找”。
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前缀和 + 二分查找：
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```python
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class Solution:
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def minSubArrayLen(self, target: int, nums: List[int]) -> int:
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s = [0] + list(accumulate(nums))
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n = len(nums)
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pre_sum = [0] * (n + 1)
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for i in range(1, n + 1):
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pre_sum[i] = pre_sum[i - 1] + nums[i - 1]
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res = n + 1
81-
for i in range(1, n + 1):
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t = pre_sum[i - 1] + target
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left, right = 0, n
84-
while left < right:
85-
mid = (left + right) >> 1
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if pre_sum[mid] >= t:
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right = mid
88-
else:
89-
left = mid + 1
90-
if pre_sum[left] - pre_sum[i - 1] >= target:
91-
res = min(res, left - i + 1)
92-
return 0 if res == n + 1 else res
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ans = n + 1
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for i, v in enumerate(s):
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t = v + target
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j = bisect_left(s, t)
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if j != n + 1:
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ans = min(ans, j - i)
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return 0 if ans == n + 1 else ans
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```
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“滑动窗口”。
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滑动窗口：
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```python
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class Solution:
@@ -114,38 +112,38 @@ class Solution:
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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“前缀和 + 二分查找”。
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前缀和 + 二分查找：
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```java
120118
class Solution {
121119
public int minSubArrayLen(int target, int[] nums) {
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int n = nums.length;
123-
int[] preSum = new int[n + 1];
124-
for (int i = 1; i <= n; ++i) {
125-
preSum[i] = preSum[i - 1] +nums[i - 1];
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int[] s = new int[n + 1];
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for (int i = 0; i < n; ++i) {
123+
s[i + 1] = s[i] + nums[i];
126124
}
127-
int res = n + 1;
128-
for (int i = 1; i <= n; ++i) {
129-
int t = preSum[i - 1] + target;
130-
int left = 0, right = n;
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int ans = n + 1;
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for (int i = 0; i < n; ++i) {
127+
int t = s[i] + target;
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int left = 0, right = n + 1;
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while (left < right) {
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int mid = (left + right) >> 1;
133-
if (preSum[mid] >= t) {
131+
if (s[mid] >= t) {
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right = mid;
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} else {
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left = mid + 1;
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}
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}
139-
if (preSum[left] - preSum[i - 1] >= target) {
140-
res = Math.min(res, left - i + 1);
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if (left != n + 1) {
138+
ans = Math.min(ans, left - i);
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}
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}
143-
return res == n + 1 ? 0 : res;
141+
return ans == n + 1 ? 0 : ans;
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}
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}
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```
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“滑动窗口”。
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滑动窗口：
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```java
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class Solution {
@@ -168,6 +166,33 @@ class Solution {
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### **C++**
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前缀和 + 二分查找：
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```cpp
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class Solution {
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public:
174+
int minSubArrayLen(int target, vector<int>& nums) {
175+
int n = nums.size();
176+
vector<int> s(n + 1);
177+
for (int i = 0; i < n; ++i) s[i + 1] = s[i] + nums[i];
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int ans = n + 1;
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for (int i = 0; i < n; ++i)
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{
181+
int t = s[i] + target;
182+
auto p = lower_bound(s.begin(), s.end(), t);
183+
if (p != s.end())
184+
{
185+
int j = p - s.begin();
186+
ans = min(ans, j - i);
187+
}
188+
}
189+
return ans == n + 1 ? 0 : ans;
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}
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};
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```
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滑动窗口：
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```cpp
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class Solution {
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public:
@@ -189,8 +214,44 @@ public:
189214
};
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```
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### **Go**
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前缀和 + 二分查找：
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```go
222+
func minSubArrayLen(target int, nums []int) int {
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n := len(nums)
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s := make([]int, n+1)
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for i, v := range nums {
226+
s[i+1] = s[i] + v
227+
}
228+
ans := n + 1
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for i, v := range s {
230+
t := v + target
231+
left, right := 0, n+1
232+
for left < right {
233+
mid := (left + right) >> 1
234+
if s[mid] >= t {
235+
right = mid
236+
} else {
237+
left = mid + 1
238+
}
239+
}
240+
if left != n+1 && ans > left-i {
241+
ans = left - i
242+
}
243+
}
244+
if ans == n+1 {
245+
return 0
246+
}
247+
return ans
248+
}
249+
```
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### **C#**
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滑动窗口：
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194255
```cs
195256
public class Solution {
196257
public int MinSubArrayLen(int target, int[] nums) {

‎solution/0200-0299/0209.Minimum Size Subarray Sum/README_EN.md

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Original file line numberDiff line numberDiff line change
@@ -43,35 +43,31 @@
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## Solutions
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**Method 1: PreSum & Binary search**
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**Method 2: Slide window**
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<!-- tabs:start -->
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### **Python3**
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50-
Presum and binary search.
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PreSum & Binary search:
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5256
```python
5357
class Solution:
5458
def minSubArrayLen(self, target: int, nums: List[int]) -> int:
59+
s = [0] + list(accumulate(nums))
5560
n = len(nums)
56-
pre_sum = [0] * (n + 1)
57-
for i in range(1, n + 1):
58-
pre_sum[i] = pre_sum[i - 1] + nums[i - 1]
59-
res = n + 1
60-
for i in range(1, n + 1):
61-
t = pre_sum[i - 1] + target
62-
left, right = 0, n
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while left < right:
64-
mid = (left + right) >> 1
65-
if pre_sum[mid] >= t:
66-
right = mid
67-
else:
68-
left = mid + 1
69-
if pre_sum[left] - pre_sum[i - 1] >= target:
70-
res = min(res, left - i + 1)
71-
return 0 if res == n + 1 else res
61+
ans = n + 1
62+
for i, v in enumerate(s):
63+
t = v + target
64+
j = bisect_left(s, t)
65+
if j != n + 1:
66+
ans = min(ans, j - i)
67+
return 0 if ans == n + 1 else ans
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```
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Slide window.
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Slide window:
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```python
7773
class Solution:
@@ -91,38 +87,38 @@ class Solution:
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9288
### **Java**
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Presum and binary search.
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Presum & binary search:
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```java
9793
class Solution {
9894
public int minSubArrayLen(int target, int[] nums) {
9995
int n = nums.length;
100-
int[] preSum = new int[n + 1];
101-
for (int i = 1; i <= n; ++i) {
102-
preSum[i] = preSum[i - 1] +nums[i - 1];
96+
int[] s = new int[n + 1];
97+
for (int i = 0; i < n; ++i) {
98+
s[i + 1] = s[i] + nums[i];
10399
}
104-
int res = n + 1;
105-
for (int i = 1; i <= n; ++i) {
106-
int t = preSum[i - 1] + target;
107-
int left = 0, right = n;
100+
int ans = n + 1;
101+
for (int i = 0; i < n; ++i) {
102+
int t = s[i] + target;
103+
int left = 0, right = n + 1;
108104
while (left < right) {
109105
int mid = (left + right) >> 1;
110-
if (preSum[mid] >= t) {
106+
if (s[mid] >= t) {
111107
right = mid;
112108
} else {
113109
left = mid + 1;
114110
}
115111
}
116-
if (preSum[left] - preSum[i - 1] >= target) {
117-
res = Math.min(res, left - i + 1);
112+
if (left != n + 1) {
113+
ans = Math.min(ans, left - i);
118114
}
119115
}
120-
return res == n + 1 ? 0 : res;
116+
return ans == n + 1 ? 0 : ans;
121117
}
122118
}
123119
```
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125-
Slide window.
121+
Slide window:
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127123
```java
128124
class Solution {
@@ -145,6 +141,33 @@ class Solution {
145141

146142
### **C++**
147143

144+
Presum & binary search:
145+
146+
```cpp
147+
class Solution {
148+
public:
149+
int minSubArrayLen(int target, vector<int>& nums) {
150+
int n = nums.size();
151+
vector<int> s(n + 1);
152+
for (int i = 0; i < n; ++i) s[i + 1] = s[i] + nums[i];
153+
int ans = n + 1;
154+
for (int i = 0; i < n; ++i)
155+
{
156+
int t = s[i] + target;
157+
auto p = lower_bound(s.begin(), s.end(), t);
158+
if (p != s.end())
159+
{
160+
int j = p - s.begin();
161+
ans = min(ans, j - i);
162+
}
163+
}
164+
return ans == n + 1 ? 0 : ans;
165+
}
166+
};
167+
```
168+
169+
Slide window:
170+
148171
```cpp
149172
class Solution {
150173
public:
@@ -166,8 +189,44 @@ public:
166189
};
167190
```
168191

192+
### **Go**
193+
194+
Presum & binary search:
195+
196+
```go
197+
func minSubArrayLen(target int, nums []int) int {
198+
n := len(nums)
199+
s := make([]int, n+1)
200+
for i, v := range nums {
201+
s[i+1] = s[i] + v
202+
}
203+
ans := n + 1
204+
for i, v := range s {
205+
t := v + target
206+
left, right := 0, n+1
207+
for left < right {
208+
mid := (left + right) >> 1
209+
if s[mid] >= t {
210+
right = mid
211+
} else {
212+
left = mid + 1
213+
}
214+
}
215+
if left != n+1 && ans > left-i {
216+
ans = left - i
217+
}
218+
}
219+
if ans == n+1 {
220+
return 0
221+
}
222+
return ans
223+
}
224+
```
225+
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### **C#**
170227

228+
Slide window:
229+
171230
```cs
172231
public class Solution {
173232
public int MinSubArrayLen(int target, int[] nums) {

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