# 13086 - Golden Ratio Overheat >author: Utin ###### tags: `recursion` --- ## Brief See the code below Similar to 12602 OuQ String ## Solution 0 ```c= #include <stdio.h> #include <string.h> int T, n; char f0[2001], f1[2001]; long long int k, len[61]; char search(int n, long long int k); int main() { scanf("%d", &T); while (T--) { scanf("%s %s %d %lld", f0, f1, &n, &k); len[0] = strlen(f0); len[1] = strlen(f1); for (int i = 2; i <= n; i++) { len[i] = len[i-1] + len[i-2]; } char ans = search(n, k); printf("%c\n", ans); } } char search(int n, long long int k) { if (n == 0) return f0[k]; if (n == 1) return f1[k]; if (k < len[n-2]) return search(n-2, k); return search(n-1, k-len[n-2]); } // By Utin ``` ## Reference