Codeforces Round #453 (Div. 2) A

暴力涂色

考虑边界

#include<iostream>#include<algorithm>#include<iomanip>#include<cstdio>#include<cstdlib>#include<cstring>#include<string>#include<cmath>#include<set>#include<queue>#include<stack>#include<map>#define PI acos(-1.0)#define in freopen("in.txt", "r", stdin)#define out freopen("out.txt", "w", stdout)#define kuaidian ios::sync_with_stdio(0);using namespace std;typedef long long ll;typedef unsigned long long ull;const int maxn = 1e4 + 7, maxd = 1e8;const ll mod = 1e9 + 7;const int INF = 0x7f7f7f7f;int n, m, b, bb;int a[maxn] = {0};int main() {    kuaidian;    cin >> n >> m;    for(int i = 0; i < n; ++i) {        cin >> b >> bb;        for(int i = b; i < bb; ++i)            a[i] = 1;    }    for(int i = 0; i < m; ++i) {        if(a[i] == 0) {            cout << "NO" << endl;            return 0;        }    }    cout << "YES" << endl;    return 0;}