willcool4ever • malloc()--realloc()--calloc()

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <stdio.h>
#include <cstring>
using namespace std;

int main ()
{
    int a,b;
    scanf("%d %d",&a,&b);

    /*  malloc()用法 */
    //int *p = (int *)malloc(a*sizeof(int));
    //memset(p,0,a*sizeof(int));

    /*  calloc()用法 */
    int *p = (int *)calloc(a,sizeof(int));
    /*  realloc()用法 */
    p = (int *) realloc(p,(a+b)*sizeof(int));

    memset(p,0,(a+b)*sizeof(int));
    for
        (int i = 0; i < (a+b); ++i)
    {
        printf("%d",p[i]);
    }
    free(p);
    return 0;
}