c/c++ 杂项知识点

1. 如何动态申请二维数组空间？

/****************************************
* File Name: arr.cpp
* Author: sky0917
* Created Time: 2014年04月19日 15:21:54
****************************************/
#include <cstdio>
using namespace std;

const int N = 5;
const int M = 7;

int main(){

    int **a;
    for (int i = 0; i < N; i++){
        a[i] = new int[M];
        for (int j = 0; j < M; j++){
            a[i][j] = i*M + j;
            printf("%d%c", a[i][j],j==M-1?'\n':' ');
        }
        delete a[i];
    }
    
    int **b;
    b = (int **)malloc(N * sizeof(int*));    
    for (int i = 0; i < N; i++){
        b[i] = (int *)malloc(M * sizeof(int));
        for (int j = 0; j < M; j++){
            b[i][j] = i * M + j;
            printf("%d%c",b[i][j],j==M-1?'\n':' ');
        }
        free(b[i]);
    }
    return 0;
}