uva10229-模Fibonacci

#include<stdio.h>
#include<string.h>
typedef long long ll;
ll ans[2][1], t[2][2] = {1}, s[2][2];
ll base[2][2] = {0, 1, 1, 1};
ll mod;
void copy(ll a[][2], ll b[][2])
{
    for(int i=0; i<2; i++)
        for(int j=0; j<2; j++)
            a[i][j] = b[i][j];
}
void mul(ll a[][2], ll b[][2], ll c[][2])
{
    for(int i=0; i<2; i++)
        for(int j=0; j<2; j++) 
            a[i][j] = 0;
    for(int i=0; i<2; i++)
        for(int j=0; j<2; j++)
            for(int k=0; k<2; k++)
                a[i][j] += (b[i][k] * c[k][j]) % mod;
}
int cal(ll n)
{
    if(n == 1) copy(s, base);
    else {
        cal(n/2);
        copy(t, s);
        mul(s, t, t);
        if(n % 2 == 1){
            mul(t, s, base);
            copy(s, t);
        }
    }
}
int main()
{
    int n, m;
    while(scanf("%d%d", &n, &m) == 2) {
        if(n >= 1) {
            mod = 1 << m; cal(n);
            printf("%d\n", s[0][1]%mod);
        }
        else printf("0\n");
    }
    return 0;
}