螺旋三角

簡單的思路就是先分配存儲空間，然後找規律，一個三角一個三角的往中心畫，最後輸出數組中的數據即可，話不多說，直接上代碼

public static void trianglePrint(int num){
        int[][] array = new int[num][];
        for (int i = 0; i <num; i++) {
            array[i] = new int[num-i];
        }
        for (int k = 1; k <= num;k++) {
            int i, j;
            int temp = k / 3;
            int init = (2 * num - k + 2) * (k-1) / 2+1;
            switch (k%3){
                case 1:
                    i = temp;
                    j = temp;
                    for (int n = 0; n < num - k + 1; n++) {
                        array[i][j] = init + n;
                        j++;
                    }
                    break;
                case 2:
                    i = temp+1;
                    j = num - 2 * temp-2;
                    for (int n = 0; n < num - k+1; n++) {
                        array[i][j] = init + n;
                        i++;
                        j--;
                    }
                    break;
                case 0:
                    i = num - 2 * temp;
                    j = temp - 1;
                    for (int n = 0; n < num - k + 1; n++) {
                        array[i][j] = init + n;
                        i--;
                    }
                    break;
            }
        }
        for (int h = 0; h < num; h++) {
            int k = 0;
            for (; k <array[h].length-1; k++) {
                System.out.print(array[h][k]+"\t");
            }
            System.out.println(array[h][k]);
        }
    }