Submission #173468

#	Time	Username	Problem	Language	Result	Execution time	Memory
173468		Just_Solve_The_Problem	Bigger segments (IZhO19_segments)	C++11	13 / 100	2 ms	380 KiB

segments

#include <bits/stdc++.h>

#define ll long long

using namespace std;          

const int N = (int)5e5 + 7;

int n;
int a[N], dp[N], ind[N];
ll pref[N];

main() {
	scanf("%d", &n);
	for (int i = 1; i <= n; i++) {
		scanf("%d", &a[i]);
		pref[i] = pref[i - 1] + a[i];
	}
	for (int i = 1; i <= n; i++) {
		dp[i] = dp[i - 1];
		ind[i] = ind[i - 1];
		int l = 0;
		int r = i;
		while (r - l > 1) {
			int mid = (l + r) >> 1;
			if (pref[mid] * 2 - pref[ind[mid]] <= pref[i]) {
				l = mid;
			} else {
				r = mid;
			}
		}
		dp[i] = dp[l] + 1;
		ind[i] = l;
	}
	// cerr << ind[4] << endl;
	cout << dp[n];
}
/*
4
2 3 1 7
3
 
5
6 2 3 9 13
3

3
3 1 2
2
*/

Compilation message (stderr)

segments.cpp:13:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^
segments.cpp: In function 'int main()':
segments.cpp:14:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
segments.cpp:16:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
   ~~~~~^~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27