Submission #1088532

#	Time	Username	Problem	Language	Result	Execution time	Memory
1088532		Sunbae	Palembang Bridges (APIO15_bridge)	C++17	100 / 100	124 ms	8184 KiB

bridge

#include <bits/stdc++.h>
typedef long long ll;
#define F first
#define S second
#define mp make_pair
using namespace std;
using pii = pair<int,int>;
const int N = 1e5 + 5, M = 2e5 + 5;
int sz, m, med[2][N], bit[M], cp[M];
ll BIT[M], Ans[2][N];
pii A[N];
int pos(int x){ return upper_bound(cp, cp+m, x) - cp;}
void upd(int i, int v){ for(; i<M; i+=i&-i) bit[i] += v;}
void UPD(int i, ll v){ for(; i<M; i+=i&-i) BIT[i] += v;}
int qry(int i){ int res = 0; for(; i; i-=i&-i) res += bit[i]; return res;}
ll QRY(int i){ ll res = 0; for(; i; i-=i&-i) res += BIT[i]; return res;}
int _find(int k){
	int i = 0, sum = 0;
	for(int j = 18; j>=0; --j){
		if(i+(1<<j) < M && sum + bit[i+(1<<j)] < k) sum += bit[i+=(1<<j)];
	}
	return i + 1;
}
signed main(){
	int k, n; scanf("%d %d", &k, &n);
	ll tot = 0;
	for(int i = 0, p[2]; i<n; ++i){
		char c[2]; scanf(" %c %d %c %d", c, p, c+1, p+1); if(p[0] > p[1]) swap(p[0], p[1]);
		if(c[0] == c[1]) tot += p[1] - p[0];
		else{
			cp[m++] = p[0]; cp[m++] = p[1];
			A[sz++] = mp(p[0], p[1]); 
		}
	}
	auto cmp = [&](pii x, pii y){ return x.F + x.S < y.F + y.S;};
	sort(A, A+sz, cmp); sort(cp, cp+m); m = unique(cp, cp+m) - cp;
	int st = 0, ed = sz;
	for(int j = 0; j<2; ++j){
		memset(bit, 0, sizeof(bit)); memset(BIT, 0, sizeof(BIT));
		for(int i = st, cnt = 0; i != ed; !j ? ++i : --i){
			pii idx = mp(pos(A[i].F), pos(A[i].S));
			upd(idx.F, +1); upd(idx.S, +1);
			UPD(idx.F, +A[i].F); UPD(idx.S, +A[i].S);
			cnt += 2;
			int I = _find((cnt+1)/2);

			Ans[j][i] = (ll)qry(I) * (ll)cp[I-1] - QRY(I) + QRY(M-1) - QRY(I) - (ll)(qry(M-1) - qry(I)) * cp[I-1];
		}
		st = sz-1; ed = -1;
	}
	tot += sz;
	if(k == 1 || !sz){ printf("%lld", tot + Ans[0][sz-1]); return 0;}
	ll mn = 2e18;
	for(int i = 0; i+1<sz; ++i) mn = min(mn, Ans[0][i] + Ans[1][i+1]);
	printf("%lld", tot + mn);
}

Compilation message (stderr)

bridge.cpp: In function 'int main()':
bridge.cpp:25:17: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |  int k, n; scanf("%d %d", &k, &n);
      |            ~~~~~^~~~~~~~~~~~~~~~~
bridge.cpp:28:19: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |   char c[2]; scanf(" %c %d %c %d", c, p, c+1, p+1); if(p[0] > p[1]) swap(p[0], p[1]);
      |              ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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