Submission #100669

#	Time	Username	Problem	Language	Result	Execution time	Memory
100669		cki86201	Mountain Trek Route (IZhO12_route)	C++11	0 / 100	3 ms	512 KiB

route

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <math.h>
#include <assert.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <iostream>
#include <functional>
#include <unordered_set>
#include <bitset>
#include <time.h>
#include <limits.h>

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define Fi first
#define Se second
#define pb(x) push_back(x)
#define szz(x) (int)x.size()
#define rep(i,n) for(int i=0;i<n;i++)
#define all(x) x.begin(),x.end()
typedef tuple<int, int, int> t3;

int N, K;
int A[1000010];
int p[1000010]; int Find(int x) { return p[x] == x ? x : p[x] = Find(p[x]); }
int li[1000010], ri[1000010], z[1000010];
priority_queue <pii> pq;
inline int nxt_i(int i) { return i==N-1 ? 0 : i+1; }
inline int pre_i(int i) { return i==0 ? N-1 : i-1; }

int main() {
	scanf("%d%d", &N, &K);
	rep(i, N) scanf("%d", A + i);
	rep(i, N) li[i] = pre_i(i), ri[i] = nxt_i(i);
	rep(i, N) p[i] = i, z[i] = 1;
	rep(i, N) {
		int j = nxt_i(i);
		if(A[i] != A[j]) continue;
		int pi = Find(i), pj = Find(j);
		if(pi != pj) {
			p[pi] = pj; li[pj] = li[pi];
			z[pj] += z[pi];
		}
	}
	rep(i, N) if(p[i] == i) {
		if(A[i] < A[li[i]] && A[i] < A[ri[i]]) pq.push(pii(z[i], i));
	}
	ll ans = 0;
	while(!pq.empty()) {
		pii t = pq.top(); pq.pop();
		int x = t.Se;
		int mul = min(A[Find(li[x])], A[Find(ri[x])]) - A[x];
		if((ll)mul * t.Fi >= K) {
			ans += 2 * (K / t.Fi);
			break;
		}
		ans += 2 * mul;
		K -= t.Fi * mul;
		A[x] += mul;
		if(A[x] == A[Find(li[x])]) {
			int pi = Find(li[x]), pj = Find(x);
			if(pi != pj) {
				p[pi] = pj; li[pj] = li[pi];
				z[pj] += z[pi];
			}
		}
		if(A[x] == A[Find(ri[x])]) {
			int pi = Find(x), pj = Find(ri[x]);
			if(pi != pj) {
				p[pi] = pj; li[pj] = li[pi];
				z[pj] += z[pi];
			}
		}
		x = Find(x);
		if(A[x] < A[Find(li[x])] && A[x] < A[Find(ri[x])]) pq.push(pii(z[x], x));
	}
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

route.cpp: In function 'int main()':
route.cpp:41:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &N, &K);
  ~~~~~^~~~~~~~~~~~~~~~
route.cpp:42:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  rep(i, N) scanf("%d", A + i);
            ~~~~~^~~~~~~~~~~~~

• Subtask 1: 0 / 100