小红书 第一题第三题AC代码

第一题

#include <iostream>
#include <string>

using namespace std;

int main() {
    string str; cin >> str;
    string res = "";
    int count = 0;
    for(char ch : str){
        if(ch == '('){
            ++count;
        }else if(ch == ')'){
            --count;
        }else if(count == 0){
            if(ch == '<'){
                if(res.size() > 0) res.pop_back();
            }else {
                res.push_back(ch);
            }
        }
    }
    cout << res << endl;
    return 0;
}

第三题，竟然不支持使用lambda表达式，真是难受

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;


bool cmp(const pair<int, int> &a, const pair<int, int> &b){
    return a.first == b.first ? a.second < b.second : a.first < b.first;
}

int main() {
    int N; cin >> N;
    vector<pair<int, int> > data(N);
    for(int i = 0; i < N; ++i)
        cin >> data[i].first >> data[i].second;
    sort(data.begin(), data.end(), cmp);
    vector<int> ivec;
    for (int i = 0; i < N; ++i) {
        if (ivec.size() == 0 || ivec.back() <= data[i].second)
            ivec.push_back(data[i].second);
        else {
            int low = 0, high = ivec.size() - 1;
            while (low < high) {
                int mid = (low + high) / 2;
                if (ivec[mid] <= data[i].second)
                    low = mid + 1;
                else
                    high = mid;
            }
            ivec[low] =  data[i].second;
        }
    }
    cout << ivec.size() << endl;
    return 0;
}