UVa 151 - Power Crisis, https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=87

uva-151.cpp

#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <list>
#include <algorithm>
#include <string.h>
#include <string>
#include <queue>
#include <math.h>

//using namespace std;

#define FIND 13

int n;

bool solve(int* v, int pos, int m, int r) {  
    if(r == 1) return v[pos] == FIND;
    if(v[pos] == FIND) return r == 1;
    
    v[pos] = 0;
    
    int t = m;
    while(t--) {
        ++pos; 
        pos %= n;
        if(v[pos] == 0) ++t;
    }
    
    return solve(v, pos, m, --r);
}

int main(void) {
    
    while(true) {
        scanf("%d", &n);
        if(n == 0) break;
        
        int i=0;
        while(++i) {
            int v[n];
            for(int j=1; j<=n; ++j) v[j] = j + 1;
            
            if(solve(v, 0, i, n)) {
                printf("%d\n", i);
                break;
            }
        }
    }  
    
    return EXIT_SUCCESS;
}