Submission #25243

#	Time	Username	Problem	Language	Result	Execution time	Memory
25243		khsoo01	Palembang Bridges (APIO15_bridge)	C++11	100 / 100	286 ms	24188 KiB

bridge

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef tuple<ll, ll, ll> tp;
const ll inf = 1e18;

ll x, n, m, ans = inf, sub;
vector<ll> cp;
vector<tp> a;

struct segtree {
	ll val[888888], cnt[888888], lim;
	void init () {
		for(lim=1;lim<=m;lim<<=1);
		for(ll i=2*lim;--i;) {val[i] = 0; cnt[i] = 0;}
	}
	void upd (ll P, ll V) {
		P += lim;
		while(P) {val[P]+=V; cnt[P]++; P>>=1;}
	}
	ll get (ll K) {
		ll P = 1, R = 0;
		while(P < lim) {
			if(cnt[2*P] >= K) P = 2*P;
			else {K-=cnt[2*P]; R+=val[2*P]; P=2*P+1;}
		}
		return K*cp[P-lim] + R;
	}
} seg;

ll cpr (ll X) {
	return lower_bound(cp.begin(), cp.end(), X) - cp.begin();
}

void getdp (vector<ll> &D, vector<tp> &V) {
	seg.init();
	D.push_back(0);
	ll I = 0;
	for(auto &T : V) {
		ll _, A, B; tie(_, A, B) = T;
		A = cpr(A); B = cpr(B); ++I;
		seg.upd(A, cp[A]);
		seg.upd(B, cp[B]);
		D.push_back(seg.get(2*I)-2*seg.get(I));
	}
}

int main()
{
	scanf("%lld%lld",&x,&n);
	for(ll i=1;i<=n;i++) {
		ll A, B; char C[2], D[2];
		scanf("%s%lld%s%lld",C,&A,D,&B);
		if(C[0] == D[0]) sub += abs(A-B);
		else {
			a.push_back(make_tuple(A+B, A, B));
			cp.push_back(A); cp.push_back(B);
			sub++;
		}
	}
	sort(a.begin(), a.end());
	n = a.size();

	sort(cp.begin(), cp.end());
	cp.erase(unique(cp.begin(), cp.end()), cp.end());
	m = cp.size();

	vector<ll> pre, suf;
	getdp(pre, a);
	reverse(a.begin(), a.end());
	getdp(suf, a);

	ll ans = inf;
	for(ll i=0;i<=n;i++) {
		ans = min(ans, pre[i]+suf[n-i]);
	}
	printf("%lld\n",(x==1?pre[n]:ans)+sub);
}

Compilation message (stderr)

bridge.cpp: In function 'int main()':
bridge.cpp:50:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld%lld",&x,&n);
                         ^
bridge.cpp:53:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s%lld%s%lld",C,&A,D,&B);
                                  ^

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 9 / 9
• Subtask 4: 32 / 32
• Subtask 5: 37 / 37