ZOJ 3702 Fibonacci

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int main(){
    int numCase , i ,j ,t ,G;
    long long b[30];
    int array[30];
    array[0] = 0;
    array[1] = 1;
    for(i = 2 ; i <= 20 ; i++)
        array[i] = array[i-1] + array[i-2];
    scanf("%d",&numCase);
    while(numCase--){
        memset(b,0,sizeof(b));
        scanf("%d%d%d",&i,&G,&j);
        if((G - array[i-1]) % array[i] == 0 && (G - array[i-1]) / array[i] >= 1){
            // 满足存在t 并且，由题意可得 t>=1
            t = (G - array[i-1]) / array[i];
            b[0] = 1;
            b[1] = t;
            for(int k = 2 ; k <= 20 ; k++)
                b[k] = b[k-1] + b[k-2];
            printf("%lld\n",b[j]);
        }
        else{
            printf("-1\n");
        }
    }
    return 0;
}