Submission #40219

#	Time	Username	Problem	Language	Result	Execution time	Memory
40219		jackyliuxx	The Big Prize (IOI17_prize)	C++14	97.42 / 100	29 ms	2420 KiB

prize

#include "prize.h"
#include <map>
#include <iostream>
using namespace std;

map<int, pair<int, int>> resmp;

pair<int, int> myask(int i) {
    if (resmp.find(i) == resmp.end()) {
        auto r = ask(i);
        resmp[i] = {r[0], r[1]};
    }
    return resmp[i];
}
 
int gogo(int fr, int to, int lc, int rc, int mxc) {
    if (lc + rc == mxc) {
        return -1;
    }
    int mid = (fr + to) / 2;
    int lto = mid, rfr = mid + 1;
    int n = to - fr;
    for (int i = 0; i < n; i++) {
        if (i & 1) {
            mid -= i;
        } else {
            mid += i;
        }
        lto = min(lto, mid);
        rfr = max(rfr, mid + 1);
        auto res = myask(mid);
        int c = res.first + res.second;
        if (c == 0) {
            return mid;
        } else if (c == mxc) {
            int lrc, rlc;
            if (mid == lto) {
                lrc = res.second;
                rlc = res.first + i;
            } else {
                lrc = res.second + i;
                rlc = res.first;
            }
            int lrt = gogo(fr, lto, lc, lrc, mxc);
            if (lrt != -1) {
                return lrt;
            } else {
                return gogo(rfr, to, rlc, rc, mxc);
            }
        }
    }
    return -1;
}
 
int find_best(int n) {
    resmp.clear();
    int mxc = 0;
    int lc = 0;
    for(int i = 0; i < n && i < 500; i++) {
		auto res = myask(i);
        lc = res.first;
		if(res.first + res.second == 0)
			return i;
        if (res.first + res.second > mxc) {
            mxc = res.first + res.second;
        }
    }
    return gogo(0, n, 0, 0, mxc);
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:58:9: warning: variable 'lc' set but not used [-Wunused-but-set-variable]
     int lc = 0;
         ^

• Subtask 1: 20 / 20
• Subtask 2: 77.42 / 80