HDU 4965 Fast Matrix Calculation 矩阵乘法 乘法结合律

一种奇葩的写法，纪念一下当时的RE。

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <cstdlib>
 #include <cmath>
 #include <algorithm>
 #include <string>
 #include <queue>
 #include <stack>
 #include <vector>
 #include <map>
 #include <set>
 #include <functional>
 #include <cctype>
 #include <time.h>

 using namespace std;

 const int INF = <<;
 const int MAXN = ;

 struct Matrix {
     int a[MAXN][MAXN];
     int col, row;
 };

 Matrix tMu;

 void multiplication(const Matrix &x, const Matrix &y) {
     tMu.row= x.row; tMu.col = y.col;
     for (int i = ; i < tMu.row; i++)
         for (int j = ; j < tMu.row; j++) {
             tMu.a[i][j] = ;
             for (int k = ; k < x.col; k++)
                 tMu.a[i][j] = (tMu.a[i][j]+x.a[i][k]*y.a[k][j])%;
         }
 }

 Matrix a, b, ONE;
 Matrix t;
 Matrix tmp, res;

 int n, k;

 void pow(const Matrix &x, int d) {
     res = ONE; res.col = res.row = x.col;
     tmp = x;
     while (d>) {
         if (d&) {
             multiplication(res, tmp);
             res = tMu;
         }
         multiplication(tmp, tmp);
         tmp = tMu;
         d >>= ;
     }
 }

 void solve() {
     multiplication(b, a);
     t = tMu;
     pow(t, n*n-);
     t = res;
     multiplication(a, t);
     t = tMu;
     multiplication(t, b);
     t = tMu;
     int ans = ;
     for (int i = ; i < n; i++) {
         for (int j = ; j < n; j++)
             ans += t.a[i][j];
     }
     printf("%d\n", ans);
 }

 int main() {
     #ifdef Phantom01
         freopen("HDU4965.txt", "r", stdin);
     #endif //Phantom01

     for (int i = ; i < MAXN; i++) {
         for (int j = ; j < MAXN; j++)
             ONE.a[i][j] = ;
         ONE.a[i][i] = ;
     }

     while (scanf("%d%d", &n, &k)!=EOF && !(n==&&k==)) {
         a.row = b.col = n;
         a.col = b.row = k;
         for (int i = ; i < n; i++)
             for (int j = ; j < k; j++)
                 scanf("%d", &a.a[i][j]);
         for (int i = ; i < k; i++)
             for (int j = ; j < n; j++)
                 scanf("%d", &b.a[i][j]);
         solve();
     }

     return ;
 }