C语言内存管理

#include <stdlib.h>#include <stdio.h>//指针的指针void changeArr(int **p){    int *arr;    arr = malloc(2*sizeof(int));    arr[0] = 1;    arr[1] = 2;    //free(*p);    *p = arr;}int main(){    int **p;    int *arr;    p = malloc(10*sizeof(int));    *p = malloc(2*sizeof(int));    arr = malloc(2*sizeof(int));    arr[0] = 3;    arr[1] = 4;    *p = arr;    changeArr(p);//  realloc(arr,20*sizeof(int));    printf("%d and %d \n",(*p)[0],(*p)[1]);    free(arr);}