2022.将一维数组转变为二维数组.md

方法一：模拟

class Solution {
    public int[][] construct2DArray(int[] original, int m, int n) {
        if (m * n != original.length) return new int[0][0];
        int rowIdx = 0, colIdx = 0;
        int[][] res = new int[m][n];
        for (int i = 0; i < original.length; i++) {
            res[rowIdx][colIdx] = original[i];
            if (++colIdx == n) {
                colIdx = 0;
                rowIdx++;
            }
        }
        return res;
    }
}