Submission #1155783

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Source Code Expand

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <functional>
#include <cmath>
#include <complex>
#include <cctype>
#include <cassert>
#include <sstream>
#include <ctime>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<pii, int> P;

#define INF (1<<29)
#define INFL (1ll<<60)
#define EPS (1e-8)
#define PI (acos(-1))
const ll MOD = 1000000007ll;

int n;
P t[112345];
vector<int> v[1123456];
int dp[1123456];

int main() {
	cin >> n;
	REP(i, n) {
		int a, b;
		scanf("%d %d", &a, &b);
		v[a].push_back(b);
		t[i] = P(pii(a, i + 1), b);
	}
	
	for (int i = 1000000; i >= 0; i--) {
		chmax(dp[i], dp[i + 1]);
		REP(j, v[i].size()) chmax(dp[i], dp[v[i][j]] + 1);
	}
	
	sort(t, t + n);
	
	vector<int> ans;
	int now = 0;
	
	REP(i, n) {
		int l = t[i].first.first;
		int r = t[i].second;
		int pos = t[i].first.second;
		
		if (l < now) continue;
		if (ans.size() + 1 + dp[r] != dp[0]) continue;
		
		P mi = P(pii(pos, r), i);
		
		while (true) {
			i++;
			if (i < n) break;
			
			r = t[i].second;
			pos = t[i].first.second;
			
			if (ans.size() + 1 + dp[r] != dp[0]) break;
			chmin(mi, P(pii(pos, r), i));
		}
		
		ans.push_back(mi.first.first);
		now = mi.first.second;
		i = mi.second;
	}
	
	cout << ans.size() << endl;
	REP(i, ans.size()) printf("%d%c", ans[i], i == ans.size() - 1 ? '\n' : ' ');
	
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:46:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &a, &b);
                         ^

Judge Result