Added solution of sumOfTwoIntegers

Author: nhistory

sum-of-two-integers/nhistory.js

@@ -0,0 +1,16 @@
+var getSum = function (a, b) {
+  while (b !== 0) {
+    if (b > 0) {
+      a++;
+      b--;
+    } else {
+      b++;
+      a--;
+    }
+  }
+  return a;
+};
+
+// |b| is absolute value of b
+// TC: O(|b|)
+// SC: O(1)