Submission #138995

#	Time	Username	Problem	Language	Result	Execution time	Memory
138995		MAMBA	Mechanical Doll (IOI18_doll)	C++17	6 / 100	131 ms	14744 KiB

doll

#include "doll.h"
#include <bits/stdc++.h>

using namespace std;

#define rep(i , j , k) for(int i = j; i < (int)k; i++)
#define pb push_back

typedef vector<int> vi;

const int N = 2e5 + 10;

vi C , X  ,Y, nx[N];

int n, cnt = 1;

inline int inve(int sz , int l) {
	int res = 0;
	rep(i , 0 , sz)
		if (l & (1 << i))
			res ^= (1 << (sz - 1 - i));
	return res;
}

int build2(vi &vec , int l = 0, int r = -1) {
	if (r == -1) r = vec.size();
	if (l == r - 1) return vec[inve(__builtin_ctz(vec.size()), l)];
	int mid = l + r >> 1;
	int me = cnt++;
	X.pb(0), Y.pb(0);
	int le = build2(vec , l , mid);
	int re = build2(vec , mid , r);
	X[me - 1] = le;
	Y[me - 1] = re;
	return -me;
}

void build(vi vec) {
	//if (vec.empty()) return;
	int sz = vec.size();
	if(__builtin_popcount(sz) == 1) {
		build2(vec);
		return;
	}

	for (int i = 20; ~i; i--)
		if (sz > (1 << i) - 1) {
			vi local(vec.begin() , vec.begin() + (1 << i) - 1);
			local.pb(-(cnt + (1 << i) - 1));
			build2(local);
			build(vi(vec.begin() + (1 << i) - 1 , vec.end()));
			break;
		}
}

void create_circuit(int M, vi A) {
	n = A.size();
	A.pb(0);

	rep(i , 0 , n) 
		nx[A[i]].pb(A[i + 1]);

	C.resize(M + 1);

	C[0] = A[0];

	rep(i , 1 , M + 1) {
		if (nx[i].empty()) 
			C[i] = 0;
		else if (nx[i].size() == 1) {
			C[i] = nx[i][0];
		}
		else {
			C[i] = -cnt;
			build(nx[i]);
		}
	}


	answer(C , X , Y);
	return;
}

Compilation message (stderr)

doll.cpp: In function 'int build2(vi&, int, int)':
doll.cpp:28:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   28 |  int mid = l + r >> 1;
      |            ~~^~~

• Subtask 1: 2 / 2
• Subtask 2: 4 / 4
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 18
• Subtask 6: 0 / 56