Submission #790140

#	Time	Username	Problem	Language	Result	Execution time	Memory
790140		PoonYaPat	Sorting (IOI15_sorting)	C++14	54 / 100	2 ms	596 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> pii;

int n,m,b[200005],x[200005],y[200005],p[200005];
vector<pii> ans;
int a[200005],pos[200005],val[200005],c[200005];

bool check(int h, bool mode) {
	for (int i=0; i<n; ++i) a[i]=i, val[i]=i, c[i]=b[i], p[i]=i;
	for (int i=h; i>=0; --i) swap(a[x[i]],a[y[i]]);

	vector<pii> v;
	for (int i=0; i<n; ++i) pos[c[i]]=i;
	for (int i=0; i<n; ++i) {
		if (c[i]!=a[i]) {
			v.push_back(pii(i,pos[a[i]]));
			swap(pos[a[i]],pos[c[i]]);
			swap(c[pos[c[i]]],c[i]);
		}
	}
	reverse(v.begin(),v.end());

	if (mode) {
		for (int i=0; i<=h; ++i) {
			swap(val[p[x[i]]],val[p[y[i]]]);
			swap(p[x[i]],p[y[i]]);

			if (v.size()) {
				ans.push_back(pii(val[v.back().first],val[v.back().second]));
				v.pop_back();
			} else ans.push_back(pii(0,0));
		}
	}

	if (v.size()<=h+1) return true;
	else return false;
}

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
	n=N; m=M;
	for (int i=0; i<n; ++i) b[i]=S[i], x[i]=X[i], y[i]=Y[i];

	int l=0, r=m-1;
	while (l<r) {
		int mid=(l+r)/2;
		if (check(mid,0)) r=mid;
		else l=mid+1;
	}
	check(l,1);

	for (int i=0; i<ans.size(); ++i) P[i]=ans[i].first, Q[i]=ans[i].second;
	return ans.size();
}

Compilation message (stderr)

sorting.cpp: In function 'bool check(int, bool)':
sorting.cpp:37:14: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   37 |  if (v.size()<=h+1) return true;
      |      ~~~~~~~~^~~~~
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:53:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |  for (int i=0; i<ans.size(); ++i) P[i]=ans[i].first, Q[i]=ans[i].second;
      |                ~^~~~~~~~~~~
sorting.cpp:54:17: warning: conversion from 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   54 |  return ans.size();
      |         ~~~~~~~~^~

• Subtask 1: 8 / 8
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 18 / 18
• Subtask 5: 0 / 20
• Subtask 6: 0 / 26