Submission #117459

#	Time	Username	Problem	Language	Result	Execution time	Memory
117459		tjd229	The Big Prize (IOI17_prize)	C++14	98.57 / 100	58 ms	5240 KiB

prize

#include "prize.h"
#include <vector>
#define pii pair<int,int>
using namespace std;
const int seg = 472;//473-1
int pre;
int nc;//1+2+3+4
int call;
vector<int> v[200000];
void my_ask(int i) {
	if (v[i].empty()) v[i] = ask(i),++call;
}
int search(int l,int r,int tgt) {
	int t = -1;
	while (l <= r) {
		int m = (l + r) >> 1;
		my_ask(m);
		if (v[m][0] + v[m][1] != nc) {
			t = m, r = m - 1;
			if (tgt == 1) return t;
		}
		else if (v[m][0] == pre) l = m + 1;		
		else r = m - 1;
	}
	return t;
}
int find_best(int n) {
	if (n <= 5000) {
		for (int i = 0; i < n; ++i) {
			my_ask(i);
			if (v[i][0] + v[i][1] == 0) return i;
		}
	}
	vector<pii > g;
	int i = 0, j = seg-1;
	int last = 0;
	while (i < n) {
		if (j >= n) j = n-1;
		my_ask(j);
		int s = v[j][0] + v[j][1];
		if (s == 0) return j;
		if (nc < s) nc = s;
		g.push_back({i,j});
		i += seg; j += seg;
	}
	for (i = 0; i < n && call <= seg; ++i) {
		my_ask(i);
		int s = v[i][0] + v[i][1];
		if (s == 0) return i;
		if (nc < s) nc = s;
	}
	for (;v[last].size();++last) {
		int s = v[last][0] + v[last][1];
		if (nc > s) ++pre;
	}
	for (i = 0; i < g.size();) {
		int e = g[i].second;
		if (e < last || (v[e][0]+v[e][1]==nc&&v[e][0]==pre)) {
			++i;
			continue;
		}
		int t = search(last,e,v[e][0]-pre);
		if (v[t][0] + v[t][1] == 0) return t;
		++pre;
		last = t+1;
	}
	return 0;
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:56:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i = 0; i < g.size();) {
              ~~^~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 78.57 / 80