Submission #1565001

---

Source Code Expand

#include <iostream>
#include <iomanip>
#include <string>
#include <vector>
#include <queue>
#include <algorithm>
#include <utility>
#include <cmath>
#include <map>
#include <set>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;

#define INF_LL (ll)1e18
#define INF (int)1e9
#define REP(i, n) for(int i = 0;i < (n);i++)
#define FOR(i, a, b) for(int i = (a);i < (b);i++)
#define all(x) x.begin(),x.end()
using ll = long long;
using PII = pair<int, int>;

const double eps = 1e-10;

template<typename A, typename B>inline void chmin(A &a, B b){if(a > b) a = b;}
template<typename A, typename B>inline void chmax(A &a, B b){if(a < b) a = b;}

#define fs first
#define sc second

/*
class SegTree{
private:
	vector<ll> node;
	int n;
public:
	SegTree(vector<ll> a){
		n = 1;
		while(n < a.size()) n *= 2;
		node.resize(0, 2*n-1);
		FOR(i, a.size()){
			node[n+i-1] = a[i];
		}
		for(int i = n-1
	}
};
*/

int main(void){
	int N, M;
	int a[101] = {};
	cin >> N >> M;
	REP(i, M){
		int s, g;
		cin >> s >> g;
		a[s] = max(a[s], g);
	}
	int ll = 0, last = 1;
	int cnt = 0;
	while(last < N){
		int in = -1;
		FOR(i, ll, last+1){
			in = max(in, a[i]);
		}
		if(in <= last){
			cout << "Impossible" << endl;
			return 0;
		}
		cnt++;
		last = in;
	}
	cout << cnt << endl;
}

Submission Info

Judge Result