Submission #1027198

#	Time	Username	Problem	Language	Result	Execution time	Memory
1027198		toan2602	Sure Bet (CEOI17_sure)	C++14	100 / 100	55 ms	2764 KiB

sure

#include<bits/stdc++.h>

using namespace std;
int n;
double a[100005], b[100005], pfs[100005];
void solve() {
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> a[i] >> b[i];
	sort(a+1,a+1+n, greater<>());
	sort(b+1,b+1+n, greater<>());
	for (int i = 1; i <= n; i++) pfs[i] = pfs[i-1] + b[i];
	double ra, rb, res = 0;
	ra = rb = 0;
	for (int i = 1; i <= n; i++) {
		ra += a[i], rb = 0;
		int l = 1, r = n, mid, pos=n;
		while(l <= r) {
			mid = (l+r)/2;
			if(pfs[mid] > ra) r = mid-1, pos = min(pos, mid);
			else l = mid+1;
		}
		res = max(res, min(ra-i-pos, pfs[pos]-i-pos));
		if(pos != 1) pos--, res = max(res, min(ra-i-pos, pfs[pos]-i-pos));
	}
	cout << fixed << setprecision(4) << res;
}

signed main() {
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen("input.inp","r")){
		freopen("input.inp", "r", stdin);
		freopen("output.out", "w", stdout);
	}
	int t = 1;
	// cin >> t;
	while(t--) {
		solve();
	}
}

Compilation message (stderr)

sure.cpp: In function 'int main()':
sure.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |   freopen("input.inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
sure.cpp:32:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |   freopen("output.out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 40 / 40