feat: add solutions to lc/lcof2 problems (#635)

* lcof2 No.010.Subarray Sum Equals K
* lc No.0525 & lcof2 No.011.Contiguous Array

Author: Yousazoe

lcof2/剑指 Offer II 010. 和为 k 的子数组/README.md

@@ -99,6 +99,31 @@ func subarraySum(nums []int, k int) int {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    int subarraySum(vector<int>& nums, int k) {
+        if (nums.size() < 0) return 0;
+
+        int presum = 0;
+        int count = 0;
+        unordered_map<int, int> mp;
+        mp[0] = 1;
+
+        for (int right = 0; right < nums.size(); right++) {
+            presum += nums[right];
+            count += mp[presum - k];
+            mp[presum]++;
+        }
+
+        return count;
+    }
+};
+```
+
+
 ### **...**
 
 ```

lcof2/剑指 Offer II 010. 和为 k 的子数组/Solution.cpp

@@ -0,0 +1,19 @@
+class Solution {
+public:
+    int subarraySum(vector<int>& nums, int k) {
+        if (nums.size() < 0) return 0;
+
+        int presum = 0;
+        int count = 0;
+        unordered_map<int, int> mp;
+        mp[0] = 1;
+
+        for (int right = 0; right < nums.size(); right++) {
+            presum += nums[right];
+            count += mp[presum - k];
+            mp[presum]++;
+        }
+
+        return count;
+    }
+};

lcof2/剑指 Offer II 011. 0 和 1 个数相同的子数组/README.md

@@ -114,6 +114,30 @@ func max(a, b int) int {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    int findMaxLength(vector<int>& nums) {
+        int presum = 0;
+        int maxlen = 0;
+        unordered_map<int, int> mp;
+        mp[0] = -1;
+        for (int i = 0; i < nums.size(); i++) {
+            presum += nums[i] == 0? -1: 1;
+            if (mp.find(presum) != mp.end())
+                maxlen = max(maxlen, i - mp[presum]);
+            else
+                mp[presum] = i;    
+        }
+
+        return maxlen;
+    }
+};
+```
+
+
 ### **...**
 
 ```

lcof2/剑指 Offer II 011. 0 和 1 个数相同的子数组/Solution.cpp

@@ -0,0 +1,18 @@
+class Solution {
+public:
+    int findMaxLength(vector<int>& nums) {
+        int presum = 0;
+        int maxlen = 0;
+        unordered_map<int, int> mp;
+        mp[0] = -1;
+        for (int i = 0; i < nums.size(); i++) {
+            presum += nums[i] == 0? -1: 1;
+            if (mp.find(presum) != mp.end())
+                maxlen = max(maxlen, i - mp[presum]);
+            else
+                mp[presum] = i;
+        }
+
+        return maxlen;
+    }
+};

solution/0500-0599/0525.Contiguous Array/README.md

@@ -49,6 +49,30 @@
 
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    int findMaxLength(vector<int>& nums) {
+        int presum = 0;
+        int maxlen = 0;
+        unordered_map<int, int> mp;
+        mp[0] = -1;
+        for (int i = 0; i < nums.size(); i++) {
+            presum += nums[i] == 0? -1: 1;
+            if (mp.find(presum) != mp.end())
+                maxlen = max(maxlen, i - mp[presum]);
+            else
+                mp[presum] = i;    
+        }
+
+        return maxlen;
+    }
+};
+```
+
+
 ### **...**
 
 ```

solution/0500-0599/0525.Contiguous Array/README_EN.md

@@ -64,6 +64,29 @@ The length of the given binary array will not exceed 50,000.
 
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    int findMaxLength(vector<int>& nums) {
+        int presum = 0;
+        int maxlen = 0;
+        unordered_map<int, int> mp;
+        mp[0] = -1;
+        for (int i = 0; i < nums.size(); i++) {
+            presum += nums[i] == 0? -1: 1;
+            if (mp.find(presum) != mp.end())
+                maxlen = max(maxlen, i - mp[presum]);
+            else
+                mp[presum] = i;    
+        }
+
+        return maxlen;
+    }
+};
+```
+
 ### **...**
 
 ```

solution/0500-0599/0525.Contiguous Array/Solution.cpp

@@ -0,0 +1,18 @@
+class Solution {
+public:
+    int findMaxLength(vector<int>& nums) {
+        int presum = 0;
+        int maxlen = 0;
+        unordered_map<int, int> mp;
+        mp[0] = -1;
+        for (int i = 0; i < nums.size(); i++) {
+            presum += nums[i] == 0? -1: 1;
+            if (mp.find(presum) != mp.end())
+                maxlen = max(maxlen, i - mp[presum]);
+            else
+                mp[presum] = i;
+        }
+
+        return maxlen;
+    }
+};