Question

我有一个从右上角到左下角读取对角线值的java代码，但我希望代码从左上角到右下角读取值。

int [][]mat = { {1,2,3},
                {4,5,6},
                {7,8,9},
};

int N=3;

for (int s=0; s<N; s++) {
    for (int i=s; i>-1; i--) {
        System.out.print(mat[i][s-i] + " ");
    }
    System.out.println();
}

for (int s=1; s<N; s++) {
    for (int i=N-1; i>=s; i--) {
        System.out.print(mat[i][s+N-1-i] + " ");
    }
    System.out.println();
}

以上代码的输出是

1 4 2 7 5 3 8 6 9

我想要像

这样的序列

3 2 6 1 5 9 4 8 7

Answer 1

int [][]mat = { {1,2,3},
                {4,5,6},
                {7,8,9},
};

int N=3;

for (int s=N-1; s>-N; --s) {
    int iMin = s>0 ? s : 0;
    int iMax = s>0 ? N : N+s;
    for (int i=iMin; i<iMax; ++i) {
        System.out.print(mat[i-s][i] + " ");
    }
}
System.out.println();

<强>输出

3 2 6 1 5 9 4 8 7

Answer 2

我修改了你的代码以实现所需的输出。

for (int s = N - 1; s > -1; s--) {
    for (int i = s; i < N; i++) {
        System.out.print(mat[i - s][i] + " ");
    }
    System.out.println();
    }

for (int s = 1; s < N; s++) {
   for (int i = s; i < N; i++) {
        System.out.print(mat[i][i - s] + " ");
    }
    System.out.println();
}

从左上角到右下角对角地读取martix的所有元素

2 个答案: