@@ -0,0 +1,42 @@
+
+function adjust(num, limit, s) {
+let sn = parseInt(s);
+let sufMod = 10 ** s.length;
+let suf = num % sufMod;
+num = Math.floor(num / sufMod);
+
+if (suf < sn) --num;
+
+if (num <= 0) return num + 1;
+
+let sNum = num.toString();
+let res = sNum.charCodeAt(0) - 48;
+let tight = 1;
+
+if (res > limit) {
+return (limit + 1) ** sNum.length;
+}
+
+for (let i = 1; i < sNum.length; ++i) {
+res *= (limit + 1);
+
+if (tight) {
+let c = sNum.charCodeAt(i) - 48;
+if (c > limit) {
+tight = 0;
+res += limit + 1;
+} else {
+res += c;
+}
+}
+}
+
+return res + tight;
+}
+
+var numberOfPowerfulInt = function (start, finish, limit, s) {
+--start;
+let ss = adjust(start, limit, s);
+let ff = adjust(finish, limit, s);
+return ff - ss;
+};