Submission #643098

#	Time	Username	Problem	Language	Result	Execution time	Memory
643098		TimDee	Climbers (RMI18_climbers)	C++17	0 / 100	3 ms	356 KiB

climbers

#include <bits/stdc++.h>
using namespace std;
#define forn(i,n) for (int i=0; i<n; ++i)

void solve() {

	int n; cin>>n;
	vector<int> a(n); forn(i,n) cin>>a[i];
	int ans=0;
	int l=0,r=n-1;
	int h=0;
	while (l<r) {
		if (a[l+1]>=h) {
			if (a[r-1]>=h) {
				if (a[l+1]<a[r-1]) {
					ans+=a[l+1]-h;
					h=a[l+1];
					++l;
				} else if (a[l+1]>a[r-1]) {
					ans+=a[r-1]-h;
					h=a[r-1];
					--r;
				} else {
					ans+=a[l+1]-h;
					h=a[l+1];
					++l, --r;
				}
			} else {
				if (a[l]<a[r-1]) {
					ans+=h-a[r-1];
					h=a[r-1];
					--r;
				} else if (a[l]>a[r-1]) {
					ans+=h-a[l];
					h=a[l];
					if ((l==0) || a[l-1]>a[l]) {
						cout<<"NO\n";
						return;
					} else --l;
				} else {
					ans+=h-a[l];
					h=a[l];
					--r;
				}
			}
		} else {
			if (a[r-1]<h) {
				if (a[l+1]>a[r-1]) {
					ans+=h-a[l+1];
					h=a[l+1];
					++l;
				} else if (a[l+1]<a[r-1]) {
					ans+=h-a[r-1];
					h=a[r-1];
					--r;
				} else {
					ans+=h-a[l+1];
					h=a[l+1];
					++l,--r;
				}
			} else {
				if (a[r]<a[l+1]) {
					ans+=h-a[l+1];
					h=a[l+1];
					++l;
				} else if (a[r]>a[l+1]) {
					ans+=h-a[r];
					h=a[r];
					if ((r==n-1) || a[r+1]>a[r]) {
						cout<<"NO\n";
						return;
					} else ++r;
				} else {
					ans+=h-a[r];
					h=a[r];
					++l;
				}
			}
		}
		//cout<<l<<' '<<r<<' '<<ans<<' '<<h<<'\n';
	}
	cout<<ans;
}

int32_t main() {
	solve();
	return 0;
}

• Subtask 1: 0 / 25
• Subtask 2: 0 / 25
• Subtask 3: 0 / 50