行列式对角线的计算(代码实现)

Posted 2022-04-29 hello-dummy

// 主对角线法 ，不管是怎么求值，row始终是要往下移  
int CalDeterminant(
int (*data)[vertexNum|1],// 行列式，下标从1开始 
int n// 行列式大小 
) 
    
    int r0, r1,row,col;
    int value;
    // 反
    r0 = 0;
    for (int i = n; i >= 1; i--) 
        row = 1;
        col = i;
        value = 1;
        for (int j = 1; j <= n; j++) 
            value *= arr[row][col];
            row++;
            col--;
            if (col == 0) col = n;
        
        r0 += value;
    
    
    // 正
    r1 = 0;
    for (int i = 1; i <= n; i++) 
        row = 1;
        col = i;
        value = 1;
        for (int j = 1; j <= n; j++) 
            value *= arr[row][col];
            row++;
            col = (col+1)%(n+1);
            if (col == 0) col = 1;
        
        r1 += value;
    
    
    return r1+r0;