feat: Add cpp solution to lc problem No.0008

Author: gaganxsaini

solution/0000-0099/0008.String to Integer (atoi)/README.md

@@ -356,6 +356,35 @@ class Solution {
 }
 ```
 
+#### C++
+```c++
+class Solution {
+public:
+    int myAtoi(string s) {
+        int i = 0, n = s.size();
+        while (i < n && s[i] == ' ')
+            ++i;
+        
+        int sign = 1;
+        if (i < n && (s[i] == '-' || s[i] == '+')) {
+            sign = s[i] == '-' ? -1 : 1;
+            ++i;
+        }
+
+        int res = 0;
+        while (i < n && isdigit(s[i])) {
+            int digit = s[i] - '0';
+            if (res > INT_MAX / 10 || (res == INT_MAX / 10 && digit > INT_MAX % 10)) {
+                return sign == 1 ? INT_MAX : INT_MIN;
+            }
+            res = res * 10 + digit;
+            ++i;
+        }
+        return res * sign;
+    }
+};
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/0000-0099/0008.String to Integer (atoi)/README_EN.md

@@ -352,6 +352,35 @@ class Solution {
 }
 ```
 
+#### C++
+```c++
+class Solution {
+public:
+    int myAtoi(string s) {
+        int i = 0, n = s.size();
+        while (i < n && s[i] == ' ')
+            ++i;
+        
+        int sign = 1;
+        if (i < n && (s[i] == '-' || s[i] == '+')) {
+            sign = s[i] == '-' ? -1 : 1;
+            ++i;
+        }
+
+        int res = 0;
+        while (i < n && isdigit(s[i])) {
+            int digit = s[i] - '0';
+            if (res > INT_MAX / 10 || (res == INT_MAX / 10 && digit > INT_MAX % 10)) {
+                return sign == 1 ? INT_MAX : INT_MIN;
+            }
+            res = res * 10 + digit;
+            ++i;
+        }
+        return res * sign;
+    }
+};
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/0000-0099/0008.String to Integer (atoi)/Solution.cpp

@@ -0,0 +1,25 @@
+class Solution {
+public:
+    int myAtoi(string s) {
+        int i = 0, n = s.size();
+        while (i < n && s[i] == ' ')
+            ++i;
+        
+        int sign = 1;
+        if (i < n && (s[i] == '-' || s[i] == '+')) {
+            sign = s[i] == '-' ? -1 : 1;
+            ++i;
+        }
+
+        int res = 0;
+        while (i < n && isdigit(s[i])) {
+            int digit = s[i] - '0';
+            if (res > INT_MAX / 10 || (res == INT_MAX / 10 && digit > INT_MAX % 10)) {
+                return sign == 1 ? INT_MAX : INT_MIN;
+            }
+            res = res * 10 + digit;
+            ++i;
+        }
+        return res * sign;
+    }
+};