[Niu Ke] Niu Ke Practice Game 16 (Unfinished)

A   lexicographically largest subsequence

The meaning of the question: Given a string s, s contains only lowercase letters, request the largest subsequence in lexicographical order. (Look at the example to understand)

Idea: Start the comparison from the back of this string a, first store the last letter in s, then compare the latest element in that s with the previous one in a, if a is not smaller than s, store it in s, and put This looks new~

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int inf = 0x3f3f3f3f;
char s[100007];
int main() 
{

    string a;
    while(cin>>a){
        int i,t;
        s[0]=a[a.length()-1];
        t=0;
       // cout<<a.length()<<endl;
        for(i=a.length()-2;i>=0;i--){
            if(a[i]>=s[t]){
                s[++t]=a[i];

            }
        }
        for(;t>=0;t--){
            cout<<s[t];
        }
        cout<<endl;
    }
    return 0;
}