Submission #314621

#	Time	Username	Problem	Language	Result	Execution time	Memory
314621		talant117408	Sorting (IOI15_sorting)	C++17	100 / 100	386 ms	21068 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef pair <int, int> pii;
 
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
 
inline bool isvowel(char ch){
	ch = tolower(ch);
	return (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u');
}
 
inline bool isprime(int n){
	if(n < 2 || (n%2 == 0 && n != 2)) return false;
	for(int i = 3; i*i <= n; i++)
		if(n%i == 0) return false;
	return true;
}

const int NN = 6e5+7;
int S[NN], X[NN], Y[NN], tmpS[NN], tmpos[NN];
int n;
vector <pii> res1;

bool check(int poss){
    int j;
    vector <pii> sws;
    
    for(j = 0; j < n; j++)
        tmpS[j] = S[j];
    for(j = 0; j < poss; j++)
        swap(tmpS[X[j]], tmpS[Y[j]]);
    for(j = 0; j < n; j++)
        tmpos[tmpS[j]] = j;
    
    for(j = 0; j < n; j++){
        if(tmpos[j] == j) continue;
        sws.pb(mp(tmpS[j], tmpS[tmpos[j]]));
        swap(tmpS[j], tmpS[tmpos[j]]);
        swap(tmpos[tmpS[j]], tmpos[tmpS[tmpos[j]]]);
    }
    if(sz(sws) <= poss){
        
        for(j = 0; j < n; j++){
            tmpS[j] = S[j];
            tmpos[S[j]] = j;
        }
        for(j = 0; j < sz(sws); j++){
            swap(tmpS[X[j]], tmpS[Y[j]]);
            swap(tmpos[tmpS[X[j]]], tmpos[tmpS[Y[j]]]);
            res1.pb(mp(tmpos[sws[j].first], tmpos[sws[j].second]));
            swap(tmpS[tmpos[sws[j].first]], tmpS[tmpos[sws[j].second]]);
            swap(tmpos[tmpS[tmpos[sws[j].first]]], tmpos[tmpS[tmpos[sws[j].second]]]);
        }
        
        while(sz(res1) < poss){
            res1.pb(mp(0, 0));
        }
        return 1;
    }
    return 0;
}
 
int findSwapPairs(int N, int s[], int M, int x[], int y[], int P[], int Q[]) {
    
    int i;
    n = N;
    for(i = 0; i < N; i++){
        S[i] = s[i];
    }
    for(i = 0; i < M; i++){
        X[i] = x[i];
        Y[i] = y[i];
    }
    
    int l = 0, r = M;
    int mn = 2e9;
    while(l <= r){
        int mid = (l+r) >> 1;
        res1.clear();
        if(check(mid)){
            mn = min(mid, mn);
            r = mid-1;
        }
        else{
            l = mid+1;
        }
    }
    
    for(i = 0; i < mn; i++){
        P[i] = res1[i].first;
        Q[i] = res1[i].second;
    }
    
    return mn;
}

Compilation message (stderr)

sorting.cpp: In function 'bool isvowel(char)':
sorting.cpp:23:14: warning: conversion from 'int' to 'char' may change value [-Wconversion]
   23 |  ch = tolower(ch);
      |       ~~~~~~~^~~~

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