772. 只出现一次的字符

772. 只出现一次的字符

#include <iostream>
#include <cstring>

using namespace std;

int cnt[26];
char str[100010];

int main()
{
    cin >> str;

    for (int i = 0; str[i]; i ++ ) cnt[str[i] - 'a'] ++ ;

    for (int i = 0; str[i]; i ++ )
        if (cnt[str[i] - 'a'] == 1)
        {
            cout << str[i] << endl;
            return 0;
        }

    puts("no");

    return 0;
}

第一个程序有点慢

修改后的程序是

#include <iostream>
#include <cstring>

using namespace std;

int cnt[26];
char str[100010];

int main()
{
    cin >> str;

    for (int i = 0,len=strlen(str); i<len; i ++ ) cnt[str[i] - 'a'] ++ ;

    for (int i = 0,len=strlen(str); i<len; i ++ )
        if (cnt[str[i] - 'a'] == 1)
        {
            cout << str[i] << endl;
            return 0;
        }

    puts("no");

    return 0;
}

标签：字符,cnt,一次,772,int,char,++,str,include
来源： https://blog.csdn.net/qq_38054511/article/details/113571951