题解 | 排序危机——stable_sort最简写法

#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

struct node{
    char c;
    int p = 0;
};
int main() {
    int n;cin>>n;
    string s;cin>>s;
    vector<node> a(n);
    for(int i = 0;i < n;++i){
        if(s[i] >= 'a' && s[i] <= 'z') a[i] = {s[i], -1};
        else if(s[i] >= 'A' && s[i] <= 'Z') a[i] = {s[i], 1};
        else a[i] = {s[i], 0};
    }
    stable_sort(a.begin(), a.end(),[&](node a, node b){
        return a.p < b.p;
    });
    for(auto i : a) cout<<i.c;
}
// 64 位输出请用 printf("%lld")