範例程式碼 uva10229
//uva10229
#include <stdio.h>
unsigned long long matrix[2][2] = {{1, 1}, {1, 0}};
void multiply(unsigned long long F[2][2], unsigned long long M[2][2], int m) {
unsigned long long x = (F[0][0] * M[0][0] + F[0][1] * M[1][0]) % (1ULL << m);
unsigned long long y = (F[0][0] * M[0][1] + F[0][1] * M[1][1]) % (1ULL << m);
unsigned long long z = (F[1][0] * M[0][0] + F[1][1] * M[1][0]) % (1ULL << m);
unsigned long long w = (F[1][0] * M[0][1] + F[1][1] * M[1][1]) % (1ULL << m);
F[0][0] = x;
F[0][1] = y;
F[1][0] = z;
F[1][1] = w;
}
void power(unsigned long long F[2][2], unsigned long long n, int m) {
if (n == 0 || n == 1) return;
unsigned long long M[2][2] = {{1, 1}, {1, 0}};
power(F, n / 2, m);
multiply(F, F, m);
if (n % 2 != 0) multiply(F, M, m);
}
unsigned long long fibonacciModM(unsigned long long n, int m) {
unsigned long long F[2][2] = {{1, 1}, {1, 0}};
if (n == 0) return 0;
power(F, n - 1, m);
return F[0][0] % (1ULL << m);
}
int main() {
unsigned long long n;
int m;
while (scanf("%llu %d", &n, &m) != EOF) {
printf("%llu\n", fibonacciModM(n, m));
}
return 0;
}