【leetcode】矩阵对角线元素的和

int diagonalSum(int** mat, int matSize, int* matColSize){
    int row=0,col1=0,col2=(*matColSize)-1,sum=0;
    while(row<matSize && col1<*matColSize && col2>=0)
    {
        sum += (col1 == col2)? mat[row][col1]: mat[row][col1]+mat[row][col2];
        row++,col1++,col2--;
    }
    return sum;
}