笔试题-----字符串消重

#include <iostream>
#include<string>
#include<stdio.h>

using namespace std;
int main()
{
    int a[100];
    memset(a, 0, sizeof(a));
    char num[1000];
    cin >> num;
    int j = 0;
    for (int i = 0; i < strlen(num); i++)
    {
        if (num[i] >= 97&&num[i]<=122)
        {
            num[i] = num[i] - 32;
        }
        else if (a[num[i]] == 0)
        {
            a[num[i]] = 1;
            num[j++] = num[i];
        }
    }
    num[j] = ‘\0‘;
    puts(num);

}