Cod sursa(job #382679)

Utilizator CezarMocanCezar Mocan CezarMocan Data 14 ianuarie 2010 13:04:12
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.89 kb
#include <cstdio>
#include <cstring>
#define mod 666013

using namespace std;

int N, i;
int MAT[3][3], SOL[3][3];

inline void mult(int A[][3], int B[][3], int C[][3]) {
	int i, j, k;
	for (i = 0; i < 2; i++)
		for (j = 0; j < 2; j++)
			for (k = 0; k < 2; k++) 
				C[i][j] = (C[i][j] + 1LL * A[i][k] * B[k][j]) % mod;
			
}

inline void lg_power(int P, int M[][3]) {
	int C[3][3], AUX[3][3], i;
	
	memcpy(C, MAT, sizeof(MAT));
	M[0][0] = M[1][1] = 1;

	for (i = 0; (1 << i) <= P; i++) {
		if (P & (1 << i)) {
			memset(AUX, 0, sizeof(AUX));
			mult(M, C, AUX);
			memcpy(M, AUX, sizeof(AUX));
		}

		memset(AUX, 0, sizeof(AUX));
		mult(C, C, AUX);
		memcpy(C, AUX, sizeof(C));
	}
}

int main() {
	freopen("kfib.in", "r", stdin);
	freopen("kfib.out", "w", stdout);

	scanf("%d", &N);

	MAT[0][0] = 0; MAT[0][1] = 1; MAT[1][0] = 1; MAT[1][1] = 1;

	lg_power(N - 1, SOL);

	printf("%d\n", SOL[1][1]);

	return 0;
}