Submission #400066

#	Time	Username	Problem	Language	Result	Execution time	Memory
400066		juggernaut	Strange Device (APIO19_strange_device)	C++17	100 / 100	542 ms	30400 KiB

strange_device

//Another code but understand that a*b/gcd(a,b+1) is all !!!!
#include<bits/stdc++.h>
using namespace std;
#define int long long
const int inf=1e18+69;
vector<pair<int, int> >seg;
int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	int n, a, b;
	cin>>n>>a>>b;
	int gcd=__gcd(a, b+1);
	int t;
	if(a/gcd>inf/b) t=inf; //a*b/gcd>inf
	else t=(a/gcd)*b;
	for(int i=0; i<n; i++){
		int l, r; cin>>l>>r;
		if(r-l+1>=t) seg.push_back({0, t-1});
		else{
			l%=t; r%=t;
			if(l<=r) seg.push_back({l, r});
			else{
				seg.push_back({l, t-1});
				seg.push_back({0, r});
			}
		}
	}
	sort(seg.begin(), seg.end());
	int ans=0;
	for(int i=0; i<(int)seg.size(); i++){
		int l=seg[i].first, r=seg[i].second;
		int nxt=i;
		while(nxt+1<seg.size()&&seg[nxt+1].first<=r){
			r=max(r, seg[nxt+1].second); nxt++;
		}
		ans+=r-l+1; i=nxt;
	}
	cout<<ans<<endl; return 0;
}

Compilation message (stderr)

strange_device.cpp: In function 'int32_t main()':
strange_device.cpp:33:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |   while(nxt+1<seg.size()&&seg[nxt+1].first<=r){
      |         ~~~~~^~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20
• Subtask 8: 30 / 30