Submission #1085631

#	Time	Username	Problem	Language	Result	Execution time	Memory
1085631		Sunbae	Global Warming (NOI13_gw)	C++17	19 / 40	989 ms	65536 KiB

gw

#include <bits/stdc++.h>
#define z exit(0)
#define mp make_pair
#define F first
#define S second
using namespace std;
using pii = pair<int,int>;
const int N = 1e6 + 5, inf = 1e9;
int cp[N], a[N], m;
set<pii> s;
vector<int> to_remove[N];
int gw(int n, int H[]){
	for(int i = m = 0; i<n; ++i) cp[m++] = H[i];
	cp[m++] = 0;
	for(int i = 0; i<m; ++i) to_remove[i].clear(); s.clear();
	sort(cp, cp+m); m = unique(cp, cp+m) - cp;
	for(int i = 0; i<n; ++i) to_remove[a[i] = lower_bound(cp, cp+m, H[i]) - cp].push_back(i);
	for(int i = 0, j = 0; i<n; ){
		for(; j<n && a[j+1] > 0; ++j){}
		s.emplace(i, j);
		i = j+2; j = i;
	}
	int mx = (int)s.size();
	for(int t = 1; t<m; ++t){
		for(int j : to_remove[t]){
			set<pii>::iterator itr = (--s.upper_bound(mp(j, inf)));
			if(itr == s.end()) continue;
			int l = itr->F, r = itr->S;
			s.erase(itr);
			if(l <= j-1) s.emplace(l, j-1);
			if(j+1 <= r) s.emplace(j+1, r);
		}
		mx = max(mx, (int)s.size());
	}
	return mx;
}
signed main(){
	int n; scanf("%d", &n);
	int H[n];
	for(int i = 0; i<n; ++i) scanf("%d", H+i);
	printf("%d", gw(n, H));
}	

Compilation message (stderr)

gw.cpp: In function 'int gw(int, int*)':
gw.cpp:15:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   15 |  for(int i = 0; i<m; ++i) to_remove[i].clear(); s.clear();
      |  ^~~
gw.cpp:15:49: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   15 |  for(int i = 0; i<m; ++i) to_remove[i].clear(); s.clear();
      |                                                 ^
gw.cpp: In function 'int main()':
gw.cpp:38:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |  int n; scanf("%d", &n);
      |         ~~~~~^~~~~~~~~~
gw.cpp:40:32: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |  for(int i = 0; i<n; ++i) scanf("%d", H+i);
      |                           ~~~~~^~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 0 / 10
• Subtask 5: 0 / 11