Submission #50172

#	Time	Username	Problem	Language	Result	Execution time	Memory
50172		Mamnoon_Siam	커다란 상품 (IOI17_prize)	C++17	90 / 100	94 ms	5588 KiB

prize

//#pragma GCC optimize("Ofast,unroll-loops,no-stack-protector")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include "prize.h"
#include <bits/stdc++.h>
using namespace std;

#define debug(s) cout<< #s <<" = "<< s <<endl
#define all(v) (v).begin(), (v).end()
#define KeepUnique(v) (v).erase( unique(all(v)), v.end() )
#define MEMSET(a,val) memset(a, val, sizeof a)
#define PB push_back
#define endl '\n'

inline int myrand(int l, int r) {
	int ret = rand(); ret <<= 15; ret ^= rand();
	if(ret < 0) ret = -ret; ret %= (r-l+1); ret += l;
	return ret;
}
template <typename F, typename S>
ostream& operator << (ostream& os, const pair< F, S>& p) {
    return os<<"(" <<p.first<<", "<<p.second<<")";
}

const int maxn = 200010;

vector<int> memo[maxn];

int Left(int i) {
	if(memo[i].empty()) memo[i] = ask(i);
	return memo[i][0];
}
int Right(int i) {
	if(memo[i].empty()) memo[i] = ask(i);
	return memo[i][1];
}
int Total(int i) {
	if(memo[i].empty()) memo[i] = ask(i);
	return memo[i][0] + memo[i][1];
}

int find_best(int n) { int debug = 0;
	if(!debug) if(n <= 5000) { // fix
		for(int i = 0; i < n; i++) {
			if(Total(i) == 0) {
				return i;
			}
		}
	}
	int mx_tot = 0;
	for(int i = 0; i < (debug ? 1 : 500); i++) { // fix
		mx_tot = max(mx_tot, Total(i));
	}

	int now = 0;
	while(true) {
		int ret;
		if(Total(now) < mx_tot) {
			ret = now;
		} else {
			int lo = now, hi = n - 1;
			while(lo <= hi) {
				int mid = lo + hi >> 1;
				bool IsGold = ((Total(mid) < mx_tot) or (Left(mid) - Left(now) > 0));
				if(IsGold) {
					ret = mid;
					hi = mid - 1;
				} else {
					lo = mid + 1;
				}
			}
		}
		assert(ret != -1);
		if(Total(ret) == 0) return ret;
		now = ret + 1;
	}
	assert(false);
	return 0;
}

Compilation message (stderr)

prize.cpp: In function 'int myrand(int, int)':
prize.cpp:17:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(ret < 0) ret = -ret; ret %= (r-l+1); ret += l;
  ^~
prize.cpp:17:26: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  if(ret < 0) ret = -ret; ret %= (r-l+1); ret += l;
                          ^~~
prize.cpp: In function 'int find_best(int)':
prize.cpp:63:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid = lo + hi >> 1;
               ~~~^~~~
prize.cpp:75:7: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
   now = ret + 1;
   ~~~~^~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 70 / 80