2d Array in Spiral Order

Question

I\'m trying to fill an array in spiral order. So far, I can print the array in spiral order, but is there a way to modify the array so that i can fill it in spiral order and

Answer 1

int maxValue = target.length * target[0].length;

private int[][] generateMatrix(int[][] target, int level, int currentVal) {
    // always start from lower left corner in each layer
    int w = level;
    int h = target.length - level - 1;

    // fill the bottom line
    int i = 0;
    for (i = w; i < target[0].length - level && currentVal <= maxValue; i++) {
        target[h][i] = currentVal++;
    }

    w = target[0].length - level - 1;

    int j = 0;
    // fill the right line
    for (j = h - 1; j >= level && currentVal <= maxValue; j--) {
        target[j][w] = currentVal++;
    }

    h = level;

    // fill the above line
    for (i = w - 1; i >= level && currentVal <= maxValue; i--) {
        target[h][i] = currentVal++;
    }
    w = level;

    // fill the left line
    for (j = h + 1; j < target.length - level - 1 && currentVal <= maxValue; j++) {
        target[j][w] = currentVal++;
    }

    if (currentVal > maxValue)
        return target;
    return generateMatrix(target, ++level, currentVal);

}