string-to-integer-atoi solution java

string-to-integer-atoi/Solution.java

@@ -0,0 +1,32 @@
+// Accepted
+// Runtime: 1 ms
+// Memory Usage: 38.9 MB
+// Submitted: January 14th, 2021
+
+class Solution {
+    public int myAtoi(String s) {
+        int sign = 1;
+        int i = 0;
+        int result = 0;
+        if (s.length() == 0) return 0;
+        
+        // Skip through whitespace
+        while (i < s.length() && s.charAt(i) == ' ')
+            i++;
+        
+        // If there is a sign present, extract it
+        if (i < s.length() && (s.charAt(i) == '-' || s.charAt(i) == '+'))
+            if (s.charAt(i++) == '-')
+                sign = -1;
+        
+        while (i < s.length() && Character.isDigit(s.charAt(i))) {
+            if (result > Integer.MAX_VALUE / 10 || (result == Integer.MAX_VALUE / 10 && s.charAt(i) - '0' > Integer.MAX_VALUE % 10)) {
+                return (sign == 1) ? Integer.MAX_VALUE : Integer.MIN_VALUE;
+            }
+            
+            result = (result * 10) + (s.charAt(i++) - '0');
+        }
+        
+        return result * sign;
+    }        
+}