POJ 3233

矩阵分治

注意不要用 (*this) 会改变原值

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <cstdlib>
using namespace std;
int n, p, k;
struct Matrix{
	int num[35][35];
	void clear() {
		memset(num, 0, sizeof(num));
	}
	void unit() {
		clear();
		for(int i = 0; i < 35; i++) num[i][i] = 1;
	}
	Matrix operator * (const Matrix & b) {
		Matrix ans;
		ans.clear();
		for(int i = 1; i <= n; i++) {
			for(int j = 1; j <= n; j++) {
				int tmp = 0;
				for(int k = 1; k <= n; k++) {
					tmp += num[i][k] * b.num[k][j];
					tmp %= p;
				}
				ans.num[i][j] = tmp;
			}
		}
		return ans;
	}
	Matrix operator + (const Matrix & b) {
		Matrix ans;
		ans.clear();
		for(int i = 1; i <= n; i++) {
			for(int j = 1; j <= n; j++) {
				ans.num[i][j] = num[i][j] + b.num[i][j];
				ans.num[i][j] %= p;
			}
		}
		return ans;
	}
	Matrix operator ^ (int k) {
		Matrix ans, tmp = (*this);
		ans.unit();
		while(k) {
			if(k & 1) ans = ans * tmp;
			tmp = tmp * tmp;
			k >>= 1;
		}
		return ans;
	}
}a, b;
Matrix work(int cur) {
	if(cur == 1) return a;
	int mid = cur / 2;
	if(mid * 2 == cur) {
		Matrix t = work(mid);
		return t + t * (a ^ mid);
	}else {
		Matrix t = work(mid);
		return t + t * (a ^ mid) + (a ^ cur);
	}
}
int main() {
	cin >> n >> k >> p;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= n; j++) {
			cin >> a.num[i][j];
			a.num[i][j] %= p;
		}
	}
	b = work(k);
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= n; j++) {
			printf("%d ", b.num[i][j]);
		}
		printf("
");
	}
	return 0;
}