求矩阵的值_为多表代换密码解密做准备

介绍：

先输入n, 然后输入n * n 矩阵，最后输出矩阵的值。

#include <bits/stdc++.h>
using namespace std;
float result;
int A[1010][1010];
float AA[1010][1010];
int n;
void Swap(float *a, float *b)
{
    for(int i = 1; i <= n; ++i)
    {
        float temp = a[i];
        a[i] = b[i];
        b[i] = temp;
    }
}
void GetValue()
{
    float mul;
    int iter = 0;
    result = 1.0;
    for(int i = 1; i <= n; ++i)
    {
        if(AA[i][i] == 0)
        {
            for(int k = i + 1; k <= n; ++k)
            {
                if(AA[k][i] != 0)
                {
                    Swap(AA[i], AA[k]);
                    iter++;
                    break;
                }
            }
        }
        for(int k = i + 1; k <= n; ++k)
        {
            if(AA[k][i] != 0)
            {
                mul = -1 * (AA[k][i] / AA[i][i]);
                AA[k][i] = 0;
                for(int p = i + 1; p <= n; ++p)
                {
                    AA[k][p] += mul * AA[i][p];
                }
            }
        }
    }
    for(int i = 1; i <= n; ++i)
        result *= AA[i][i];
    if(iter % 2 == 1)
        result = -result;
}
void Input()
{
    scanf("%d", &n);
    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= n; ++j)
        {
            scanf("%d", &A[i][j]);
            AA[i][j] = A[i][j];
        }
}
void Putout()
{
    for(int i = 1; i <= n; ++i)
    {
        for(int j = 1; j <= n; ++j)
            cout << AA[i][j] << " ";
        cout << endl;
    }
}
int main()
{
    Input();
    GetValue();
    Putout();
    cout << result << endl;
}