atoi program: 1st commit

Author: paulsagar1a

string/AToI.java

@@ -0,0 +1,49 @@
+/*******************************************************
+ * @author SAGAR PAUL (paulsagar1a)
+ * @category string
+ *******************************************************/
+/*The atoi() function takes a string (which represents an integer) 
+as an argument and returns its value.*/
+package string;
+
+public class AToI {
+
+	public int atoi(String str) {
+		if (str == null || str.length() < 1)
+			return 0;
+		//trim white space
+		str = str.trim();
+		char flag = '+';
+		int i = 0;
+		if (str.charAt(i) == '-') {
+			flag = '-';
+			i++;
+		} else if (str.charAt(i) == '+') {
+			i++;
+		}
+		
+		long result = 0;
+		for(;i<str.length(); i++) {
+			result = result*10 + (str.charAt(i) - '0');
+		}
+		
+		if(flag == '-') {
+			result = -result;
+		}
+		
+		//handle MAX/MIN
+		if(result > Integer.MAX_VALUE)
+			return Integer.MAX_VALUE;
+		if(result < Integer.MIN_VALUE)
+			return Integer.MIN_VALUE;
+		
+		return (int)result;
+	}
+	
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+		AToI obj = new AToI();
+		System.out.println(obj.atoi("-14657"));
+	}
+
+}