From ccd114deb65c390203a6d58088a7657ef1cf9bfb Mon Sep 17 00:00:00 2001
From: Elements05 <116535389+Elements05@users.noreply.github.com>
Date: Tue, 25 Oct 2022 23:58:41 +0530
Subject: [PATCH] Create string_to_integer.cpp

string to integer atoi
---
 standard questions/string_to_integer.cpp | 49 ++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 standard questions/string_to_integer.cpp

diff --git a/standard questions/string_to_integer.cpp b/standard questions/string_to_integer.cpp
new file mode 100644
index 0000000..f198ad6
--- /dev/null
+++ b/standard questions/string_to_integer.cpp	
@@ -0,0 +1,49 @@
+class Solution {
+public:
+    int myAtoi(string s) {
+        
+        const int len = s.size();
+        
+        if(len == 0){
+            return 0;
+        }
+        
+        int index = 0;
+        while(index < len && s[index] == ' '){
+            ++index;
+        }
+
+        if(index == len){
+            return 0;
+        }
+        
+        char ch;
+        bool isNegative = (ch = s[index]) == '-';
+        
+        if(isNegative || ch == '+'){
+            ++index;
+        }
+		
+        const int maxLimit = INT_MAX / 10;
+        int result = 0;
+        while(index < len && isDigit(ch = s[index])){ 
+
+            int digit = ch - '0';
+
+            if(result > maxLimit || (result == maxLimit && digit > 7)){
+                return isNegative ? INT_MIN : INT_MAX;
+            }
+
+            result = (result * 10) + digit;
+            
+            ++index;
+        }
+        
+        return isNegative ? -result : result;
+    }
+    
+    private:
+    bool isDigit(char ch){
+        return ch >= '0' && ch <= '9';
+    }
+};