boj step 8 rework

zeta_cpp/completed/2745.cpp

@@ -0,0 +1,30 @@
+#include <iostream>
+#include <cmath>
+
+using namespace std;
+
+int translate(char c) {
+    if (48 <= c && c <= 57) {
+        return c - 48;
+    } else {
+        return c - 55;
+    }
+}
+
+int calculate(string s, int n) {
+    int l = s.length();
+    int r = 0;
+    for (int i = 0; i < l; i++) {
+        r += translate(s[i]) * pow(n, l - i - 1);
+    }
+    return r;
+}
+
+
+int main() {
+    string s;
+    int n;
+    cin >> s >> n;
+    cout << calculate(s, n);
+    return 0;
+}