Submission #951516

#TimeUsernameProblemLanguageResultExecution timeMemory
951516kilkuwuXylophone (JOI18_xylophone)C++17
100 / 100
94 ms768 KiB
#include <bits/stdc++.h>

#ifndef LOCAL
#include "xylophone.h"
#else 
void solve(int N);
int query(int s, int t);
void answer(int i, int a);

static const int __N_MAX = 5000;
static const int __Q_MAX = 10000;
static int __N;
static int __A[__N_MAX];
static bool __used[__N_MAX];
static int __query_c;
static int __answer_c;

int query(int s, int t) {
	if(__query_c >= __Q_MAX) {
		printf("Wrong Answer\n");
		exit(0);
	}
	__query_c++;
	if(!(1 <= s && s <= t && t <= __N)) {
		printf("Wrong Answer\n");
		exit(0);
	}
	int mx = 0, mn = __N + 1;
	for(int i = s - 1; i < t; i++) {
		if(mx < __A[i]) {
			mx = __A[i];
		}
		if(mn > __A[i]) {
			mn = __A[i];
		}
	}
	return mx - mn;
}

void answer(int i, int a) {
	__answer_c++;
	if(!(1 <= i && i <= __N)) {
		printf("Wrong Answer\n");
		exit(0);
	}
	if(!(1 <= a && a <= __N)) {
		printf("Wrong Answer\n");
		exit(0);
	}
	if(__used[i - 1]) {
		printf("Wrong Answer\n");
		exit(0);
	}
	if(a != __A[i - 1]) {
		printf("Wrong Answer\n");
		exit(0);
	}
	__used[i - 1] = true;
}

int main() {
	__query_c = 0;
	__answer_c = 0;
	if(scanf("%d", &__N) != 1) {
		fprintf(stderr, "Error while reading input\n");
		exit(1);
	}
	for(int i = 0; i < __N; i++) {
		if(scanf("%d", __A + i) != 1) {
			fprintf(stderr, "Error while reading input\n");
			exit(1);
		}
		__used[i] = false;
	}
	solve(__N);
	if(!(__answer_c == __N)) {
		printf("Wrong Answer\n");
		exit(0);
	}
	printf("Accepted : %d\n", __query_c);
}

#endif

#ifdef LOCAL
#include "template/debug.hpp"
#else
#define dbg(...) ;
#define timer(...) ;
#endif

void solve(int N) {
  std::vector<int> D1(N + 1);
  std::vector<int> D2(N + 1);
  
  for (int i = 2; i <= N; i++) {
    D1[i] = query(i - 1, i);
  }
  for (int i = 3; i <= N; i++) {
    D2[i] = query(i - 2, i);
  }
  std::vector<int> ans(N + 1);

  auto try_out = [&](int lb, std::vector<int>& A) -> bool {
    dbg(lb);
    std::vector<int> filled(N + 1, 0);
    A[lb] = 1;
    filled[1] = 1;

    auto in_range = [&](int x) {
      return 1 <= x && x <= N && !filled[x];
    };

    if (lb + 1 <= N) {
      A[lb + 1] = A[lb] + D1[lb + 1];
      if (!in_range(A[lb + 1])) return false;
      filled[A[lb + 1]] = 1;
    }

    if (lb - 1 >= 1) {
      A[lb - 1] = A[lb] + D1[lb];
      if (!in_range(A[lb - 1])) return false;
      filled[A[lb - 1]] = 1;
    }
    dbg(A);

    for (int L = lb - 2; L >= 1; L--) {
      A[L] = A[L + 1];
      int vp = A[L] + D1[L + 1];
      int vm = A[L] - D1[L + 1];

      if (vp > N || filled[vp]) {
        A[L] = vm;
      } else if (vm < 1 || filled[vm]) {
        A[L] = vp;
      } else {
        int tie = D2[L + 2];
        if (tie == D1[L + 1] + D1[L + 2]) {
          A[L] = (A[L + 1] < A[L + 2]) ? vm : vp; 
        } else {
          A[L] = (A[L + 1] < A[L + 2]) ? vp : vm;
        }
      }

      if (!in_range(A[L])) return false;
      filled[A[L]] = 1;
    }
    for (int R = lb + 2; R <= N; R++) {
      A[R] = A[R - 1];

      int vp = A[R] + D1[R];
      int vm = A[R] - D1[R];

      if (vp > N || filled[vp]) {
        A[R] = vm;
      } else if (vm < 1 || filled[vm]) {
        A[R] = vp;
      } else {
        int tie = D2[R];
        if (tie == D1[R] + D1[R - 1]) {
          A[R] = (A[R - 2] < A[R - 1]) ? vp : vm;
        } else {
          A[R] = (A[R - 2] < A[R - 1]) ? vm : vp;
        }
      }
      
      if (!in_range(A[R])) return false;
      

      filled[A[R]] = 1;
    }
    dbg(A);

    return true;
  };

  for (int lb = 1; lb <= N; lb++) {
    std::vector<int> A(N + 1);

    if (try_out(lb, A)) {
      ans = A;
      break;
    }

  }

  for (int i = 1; i <= N; i++) {
    answer(i, ans[i]);
  }
}
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