Add Strings

Author: parshva45

Add Strings.js

@@ -0,0 +1,31 @@
+/*Given two non-negative integers num1 and num2 represented as string, return the sum of num1 and num2.
+
+Note:
+
+The length of both num1 and num2 is < 5100.
+Both num1 and num2 contains only digits 0-9.
+Both num1 and num2 does not contain any leading zero.
+You must not use any built-in BigInteger library or convert the inputs to integer directly.*/
+
+/**
+ * @param {string} num1
+ * @param {string} num2
+ * @return {string}
+ */
+var addStrings = function(num1, num2) {
+    b = num1.length >= num2.length ? num1 : num2
+    s = num1.length < num2.length ? num1 : num2
+    ans = ""
+    carry = 0
+    for(i=b.length-1, j=s.length-1; i>=0; i--, j--){
+        if(s[j] != null)
+            sum = Number(b[i]) + Number(s[j]) + carry
+        else
+            sum = Number(b[i]) + carry
+        ans = sum%10 + ans
+        carry = parseInt(sum/10)
+    }
+    if(carry == 1)
+        return carry + ans
+    return ans
+};