ancient code

Author: ssfxz

7.cpp

@@ -0,0 +1,25 @@
+class Solution {
+public:
+    int reverse(int x) {
+        long result = 0;
+       
+        while(x != 0)
+        {
+            result *= 10;
+            result += x % 10;
+            x /= 10;
+        }
+       
+        if(x < 0)
+        {
+           result *= -1;
+        }
+       
+        if(result > 2147483647 || result < -2147483648)
+        {
+            return 0;
+        }
+       
+        return (int)result;
+    }
+};

8.cpp

@@ -0,0 +1,42 @@
+class Solution {
+public:
+    int myAtoi(string str) {
+        
+        long ret = 0;
+        bool minus = false;
+        int i = 0;
+        
+        while(isspace(str[i]))
+        {
+            ++i;
+        }
+        
+        if(str[i] == '+' || str[i] == '-')
+        {
+            if(str[i] == '-')
+            {
+                minus = true;
+            }
+            ++i;
+        }
+        
+        
+        while(isdigit(str[i]) && str[i] != '\0')
+        {
+            ret = ret * 10 + str[i] - '0';
+            ++i;
+            
+            if(ret > INT_MAX)
+            {
+                return minus ? INT_MIN : INT_MAX;
+            }
+        }
+        
+        if(minus)
+        {
+            ret *= -1;
+        }
+        
+        return (int)ret;
+    }
+};

88.cpp

@@ -0,0 +1,25 @@
+class Solution {
+public:
+    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
+        int i = m-1;
+        int j = n-1;
+        int k = m + n - 1;
+        
+        while(i >= 0 && j >= 0)
+        {
+            if(nums1[i] < nums2[j])
+            {
+                nums1[k--] = nums2[j--];
+            }
+            else
+            {
+                nums1[k--] = nums1[i--];
+            }
+        }
+        
+        while( j >= 0 )
+        {
+            nums1[k--] = nums2[j--];
+        }
+    }
+};