제출 #825441

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
825441		esomer	죄수들의 도전 (IOI22_prison)	C++17	0 / 100	4 ms	724 KiB

prison

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

using namespace std;

typedef long long ll;

int N;
vector<vector<int>> ans, inds;
vector<int> dp, which, sizes;
vector<vector<pair<int, int>>> ranges;

void calc_dp(){
	dp.assign(N+1, 1e9);
	which.assign(N+1, 1);
	for(int i = 0; i <= N; i++){
		int real = i - 2;
		if(real <= 0) dp[i] = 0;
		else{
			for(int x = 1; x <= 20; x++){
				int cll = real / x;
				if(real % x != 0) cll++;
				int needed = x + dp[cll]; 
				if(needed < dp[i]){
					which[i] = x;
					dp[i] = needed;
				}
			}
		}
	}
}

int get_groups(int i, vector<vector<pair<int, int>>>& ranges){
	pair<int, int> pr = ranges[i][0];
	int curr = 0;
	int groups = 0;
	for(int j = pr.first + 1; j < pr.second; j++) {
		curr++;
		if(curr == sizes[i + 1] || j == pr.second - 1) {
			groups++;
			curr = 0;
		}
	}
	return groups;
}

vector<vector<int>> devise_strategy(int n) {
	N = n;
	calc_dp();
	int total = N;
	while(total > 2){
		sizes.push_back(total);
		int x = which[total]; total -= 2;
		int nw = total / x;
		if(total % x != 0) nw++;
		total = nw;
	}
	sizes.push_back(total);
	ranges.assign((int)sizes.size(), {});
	inds.assign((int)sizes.size(), {});
	ranges[0].push_back({1, N});
	inds[0].push_back(0);
	ans.assign(21, vector<int>(N+1, 0));
	vector<int> col(N + 1, 0);
	int curr_ind = 1;
	for(int i = 0; i < (int)sizes.size(); i++){
		if(i == (int)sizes.size() - 1){
			for(int ind : inds[i]){
				for(pair<int, int> pr : ranges[i]){
					if(col[pr.first] == ind){
						ans[ind][pr.first] = -(ans[ind][0] + 1);
						ans[ind][pr.second] = -((1 - ans[ind][0]) + 1);
						if(pr.first > 1) ans[ind][pr.first - 1] = -(ans[ind][0] + 1);
						if(pr.second < N) ans[ind][pr.second + 1] = -((1 - ans[ind][0]) + 1);
					}else{
						for(int j = pr.first; j <= pr.second; j++) {
							if(col[j] > ind) {
								ans[ind][j] = -(ans[ind][0] + 1);
							}else{
								ans[ind][j] = -((1 - ans[ind][0]) + 1);
							}
						}
					}
				}
			}
			// cout << "i " << i << " sizes "<< sizes[i] << endl;
			// cout << "INDS: ";
			// for(int x : inds[i]) cout << x << " "; cout << endl;
			// cout << "Ranges: ";
			// for(pair<int, int> pr : ranges[i]) cout << pr.first << " " << pr.second << endl;
			// cout << "Col: ";
			// for(int x : col) cout << x << " "; cout << endl;
			continue;
		}
		int groups = get_groups(i, ranges);
		for(int j = 0; j < groups; j++){
			ans[curr_ind][0] = 1 - ans[inds[i][0]][0];
			inds[i+1].push_back(curr_ind); curr_ind++;
		}
		vector<int> nwcol(N+1, 0);
		for(int ind : inds[i]){
			for(pair<int, int> pr : ranges[i]){
				if(col[pr.first] == ind){
					ans[ind][pr.first] = -(ans[ind][0] + 1);
					ans[ind][pr.second] = -((1 - ans[ind][0]) + 1);
					if(pr.first > 1) ans[ind][pr.first - 1] = -(ans[ind][0] + 1);
					if(pr.second < N) ans[ind][pr.second + 1] = -((1 - ans[ind][0]) + 1);
					int curr = 0;
					int cind = 0;
					int lst = pr.first + 1;
					for(int j = pr.first + 1; j < pr.second; j++) {
						curr++;
						ans[ind][j] = inds[i + 1][cind];
						nwcol[j] = inds[i + 1][cind];
						if(curr == sizes[i + 1] || j == pr.second - 1) {
							ranges[i+1].push_back({lst, j});
							curr = 0; cind++; lst = j + 1;
						}
					}
				}else{
					for(int j = pr.first; j <= pr.second; j++) {
						if(col[j] > ind) {
							ans[ind][j] = -(ans[ind][0] + 1);
						}else{
							ans[ind][j] = -((1 - ans[ind][0]) + 1);
						}
					}
				}
			}
		}
		col = nwcol;
		// cout << "i " << i << " sizes "<< sizes[i] << endl;
		// cout << "INDS: ";
		// for(int x : inds[i]) cout << x << " "; cout << endl;
		// cout << "Ranges: ";
		// for(pair<int, int> pr : ranges[i]) cout << pr.first << " " << pr.second << endl;
		// cout << "Col: ";
		// for(int x : col) cout << x << " "; cout << endl;
	}
	return ans;
}

// static constexpr int kNumPrisoners = 500;

// static void invalid_strategy(std::string message) {
//   printf("%s\n", message.c_str());
//   exit(0);
// }

// int main() {
//   int N2;
//   assert(1 == scanf("%d", &N2));
//   // printf("here\n"); return 0;
//   std::vector<std::vector<int>> strategy = devise_strategy(N2);
//   // printf("here\n"); return 0;
//   if (strategy.size() == 0) {
//     invalid_strategy("s is an empty array");
//   }
//   int x = strategy.size() - 1;
//   for (int i = 0; i <= x; ++i) {
//     if (static_cast<int>(strategy[i].size()) != N2 + 1) {
//       invalid_strategy("s[i] contains incorrect length");
//     }
//     if (strategy[i][0] < 0 || strategy[i][0] > 1) {
//       invalid_strategy("First element of s[i] is non-binary"); 
//     }
//     for (int j = 1; j <= N2; ++j) {
//       if (strategy[i][j] < -2 || strategy[i][j] > x) {
//         invalid_strategy("s[i][j] contains incorrect value");
//       }
//     }
//   }
//   // printf("here\n"); return 0;

//   FILE *log_file = fopen("log.txt","w");

//   int A, B;
//   while (1 == scanf("%d", &A) && A != -1) {
//     assert(1 == scanf("%d", &B));
//     bool answer = false;
//     int whiteboard = 0;
//     for (int i = 0; i < kNumPrisoners && !answer; ++i) {
//       int check = strategy[whiteboard][0];
//       whiteboard = strategy[whiteboard][check == 0 ? A : B];
//       if (whiteboard < 0) {
//         answer = true;
//         printf("%c\n", "BA"[whiteboard + 2]);
//       } else {
//         if (i > 0) {
//           fprintf(log_file, " ");
//         }
//         fprintf(log_file, "%d", whiteboard);
//       }
//     }
//     if (!answer) {
//       printf("X\n");
//     }
//     fprintf(log_file, "\n");
//     fflush(log_file);
//   }
// }

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