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("\n");}return 0;
}