题解 | 提取不重复的整数

#include<bits/stdc++.h>
using namespace std;
#define IOS ios_base::sync_with_stdio(false);cin.tie(nullptr)
#define INF 0x7fffffff
#define inf 0x3f3f3f3f
#define PII pair<int,int>
#define endl '\n'
#define int long long
#define double long double
#define mod 998244353
int read() {char act = 0;int f = 1, x= 0;while (act = getchar(), act < '0' && act != '-');if (act == '-') f = -1, act = getchar();x = act - '0';while (act = getchar(), act >= '0') x = x * 10 + act - '0';return x * f;}
void solve(){
    string s;
    cin>>s;
    reverse(s.begin(),s.end());
    map<char,int>mp;
    vector<char>a;
    for(int i=0;i<s.size();i++){
        if(mp[s[i]]==0){
            mp[s[i]]=1;
            a.push_back(s[i]);
        }
    }
    for(auto i:a)cout<<i;
}
signed main()
{
    IOS; 
    int t=1;
    //cin>>t;
    while(t--){
        solve();
    }

    return 0;
}