Codeforces Round #602 (Div. 2, based on Technocup 2020 Elimination Round 3) A 、B

目录

• A-Math Problem
• B-Box

这个是个人日常训练记录

A-Math Problem

给你\(n\)组边界，让你求能包含每个边界相交部分的

#include <iostream>
#include <cstdio>
using namespace std;
int t, l, r, n;

int main() {
    scanf("%d", &t);
    while(t --) {
        scanf("%d", &n);
        int a = 0, b = 0x3f3f3f3f;
        for(int i = 0; i < n; i++) {
            scanf("%d%d", &l, &r);
            a = max(l, a); b = min(b, r);
        }
        if(a < b) puts("0");
        else printf("%d\n", a - b);
    }
    
    return 0;
}

B-Box

构造题，不多写了

#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 3;

int a[N], n, t;
int ans[N], idx;

int main() {
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    cin >> t;
    while(t --) {
        set<int> se;
        cin >> n;
        
        for(int i = 1; i <= n; i++) {
            cin >> a[i];
            se.insert(i);
        }
        
        int maxn = -1; bool f = 0;
        for(int i = 1; i <= n; i++) {
            if(a[i] > maxn) {
                maxn = a[i];
                se.erase(a[i]);
                ans[++idx] = a[i];
            } else if(se.size()) {
                auto p = se.begin();
                if(maxn > *p) {
                    ans[++idx] = *p;
                    se.erase(p);
                } else {
                    f = 1; break;
                }
            } else {
                f = 1; break;
            }
        }
        if(f) cout << "-1";
        else for(int i = 1; i <= idx; i++) cout << ans[i] << ' ';
        cout << '\n';
        while(idx) ans[idx--] = 0;
    }
    
    return 0;
}