学会计算 矩阵C = A×B
核心代码：

for(int i = 0; i < n; ++i){
    for(int j = 0; j < n; ++j){
        for(int k = 0; k < n; ++k){      //矩阵C = 矩阵A × 矩阵B:
            C[i][j] += A[i][k]*B[k][j]; //C[i][j] = A的第i行×B的第j列所有对应元素
        }
    }
}

答案:

#include <iostream>
#include <cstring>
using namespace std;
const int N = 11;
int A[N][N],B[N][N],C[N][N];

int main() {
    int n,m; //n为矩阵的阶,m为矩阵的幂
    cin >> n >> m;
    memset(A,0,sizeof(A));
    //输入矩阵A
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < n; ++j){
            cin >> A[i][j];
        }
    }
    //计算m次幂
    //(1)若m为1,输出原矩阵
    if(m == 1){
        for(int i = 0; i < n; ++i){
            for(int j = 0; j < n; ++j){
                cout << A[i][j] << " ";
            }
            cout << endl;
        }
        return 0;
    }
    //(2)若m>1,计算 矩阵 C = A×B
    memcpy(B,A,sizeof(A));
    while(--m){
        memset(C,0,sizeof(C));
        for(int i = 0; i < n; ++i){
            for(int j = 0; j < n; ++j){
                for(int k = 0; k < n; ++k){      //矩阵C = 矩阵A × 矩阵B:
                    C[i][j] += A[i][k]*B[k][j]; //C[i][j] = A的第i行×B的第j列所有对应元素
                }
            }
        }
        memcpy(B,C,sizeof(C)); //这次的幂次运算结果C赋值给B
    }
    //输出矩阵C
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < n; ++j){
            cout << C[i][j] << " ";
        }
        cout << endl;
    }
    return 0;
}