Submission #297991

#	Time	Username	Problem	Language	Result	Execution time	Memory
297991		Plurm	Gondola (IOI14_gondola)	C++11	55 / 100	23 ms	3192 KiB

gondola

#include "gondola.h"
#include <cstdio>
#include <cstring>
int valid(int n, int inputSeq[])
{
	int offs = 0;
	for(int i = 0; i < n; i++){
		if(inputSeq[i] <= n) offs = (n+i-inputSeq[i]+1) % n;
	}
	for(int i = 0; i < n; i++){
		if(inputSeq[(i+offs) % n] != i+1) return 0;
	}
	return 1;
}

//----------------------

int expect[250005];
int initSeq[100005];
int replacement(int n, int gondolaSeq[], int replacementSeq[])
{
	int offs = 0;
	int dummy = 0;
	int mx = -1;
	memset(expect, -1, sizeof(expect));
	for(int i = 0; i < n; i++){
		if(gondolaSeq[i] <= n) offs = (n+i-gondolaSeq[i]+1) % n;
		else expect[gondolaSeq[i]] = i;
		if(gondolaSeq[i] > mx){
			mx = gondolaSeq[i];
			dummy = i;
		}
	}
	for(int i = 0; i < n; i++){
		initSeq[(i+offs) % n] = i+1;
	}
	int rpidx = 0;
	for(int i = n+1; i <= mx; i++){
		if(expect[i] == -1){
			replacementSeq[rpidx++] = initSeq[dummy];
			initSeq[dummy] = i;
		}else{
			replacementSeq[rpidx++] = initSeq[expect[i]];
			initSeq[expect[i]] = i;
		}
	}
	return rpidx;
}

//----------------------

const int MOD = 1e9+9;
int countReplacement(int n, int inputSeq[])
{
	if(!valid(n, inputSeq)) return 0;
	int offs = -1;
	int dummy = 0;
	int mx = -1;
	int dcnt = 0;
	memset(expect, -1, sizeof(expect));
	for(int i = 0; i < n; i++){
		if(inputSeq[i] <= n) offs = (n+i-inputSeq[i]+1) % n;
		else expect[inputSeq[i]] = i;
		if(inputSeq[i] > mx){
			mx = inputSeq[i];
			dummy = i;
		}
	}
	int ans = offs == -1 ? n : 1;
	if(offs == -1) offs = 0;
	for(int i = 0; i < n; i++){
		initSeq[(i+offs) % n] = i+1;
	}
	for(int i = 0; i < n; i++){
		if(initSeq[i] == inputSeq[i]) dcnt++;
	}
	for(int i = n+1; i <= mx; i++){
		if(expect[i] == -1){
			ans = 1ll * ans * (n-dcnt) % MOD;
		}else{
			initSeq[expect[i]] = i;
			dcnt++;
		}
	}
	return ans;
}

Compilation message (stderr)

gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:57:6: warning: variable 'dummy' set but not used [-Wunused-but-set-variable]
   57 |  int dummy = 0;
      |      ^~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 10 / 10
• Subtask 4: 5 / 5
• Subtask 5: 10 / 10
• Subtask 6: 20 / 20
• Subtask 7: 0 / 5
• Subtask 8: 0 / 15
• Subtask 9: 0 / 15
• Subtask 10: 0 / 10