Submission #248998

#	Time	Username	Problem	Language	Result	Execution time	Memory
248998		Evirir	Sorting (IOI15_sorting)	C++17	Compilation error	0 ms	0 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define watch(x) cout<<(#x)<<"="<<(x)<<'\n'
#define mset(d,val) memset(d,val,sizeof(d))
#define setp(x) cout<<fixed<<setprecision(x)
#define forn(i,a,b) for(int i=(a);i<(b);i++)
#define fore(i,a,b) for(int i=(a);i<=(b);i++)
#define pb push_back
#define F first
#define S second
#define pqueue priority_queue
#define fbo find_by_order
#define ook order_of_key
typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector<ll> vi;
typedef vector<ii> vii;
typedef long double ld;
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update> pbds;
void amin(ll &a, ll b){ a=min(a,b); }
void amax(ll &a, ll b){ a=max(a,b); }
void YES(){cout<<"YES\n";} void NO(){cout<<"NO\n";}
void SD(int t=0){ cout<<"PASSED "<<t<<endl; }
const ll INF = ll(1e18);
const int MOD = 998244353;

const bool DEBUG = 1;
const int MAXN = 200005;

int findSwapPairs(int n, int A[], int m, int X[], int Y[], int P[], int Q[])
{
	int ans=-1;
	
	bool ok=1;
	for(int i=0;i<n;i++){
		if(A[i]!=i){ ok=0; break; }
	}
	if(ok) return 0;
	
	for(int L=0,R=m-1;L<=R;)
	{
		int mid=(L+R)>>1;
		//if(DEBUG){ cout<<"---------------------------\n"; watch(mid); }
		
		int a[n], loc[n], floc[n];
		vector<int> p,q;
		for(int i=0;i<n;i++) a[i]=A[i], loc[a[i]]=i, floc[i]=i;
		for(int i=mid;i>=0;i--){
			int u=X[i], v=Y[i];
			swap(floc[u],floc[v]);
		}
		
		int ptr=0;
		for(int i=0;i<=mid;i++){
			int u=X[i], v=Y[i];
			swap(floc[u],floc[v]);
			swap(loc[a[u]],loc[a[v]]);
			swap(a[u],a[v]);
			while(ptr<n && loc[ptr]==floc[ptr]) ptr++;
			if(ptr==n){ p.pb(0); q.pb(0); }
			else{
				p.pb(loc[ptr]); q.pb(floc[ptr]);
				//if(DEBUG){cout<<"Before:\n"; watch(ptr); watch(loc[ptr]); watch(floc[ptr]); forn(i,0,n) cout<<"loc["<<i<<"]="<<loc[i]<<'\n'; forn(i,0,n) cout<<a[i]<<" "; cout<<"\n\n"; }
				swap(a[loc[ptr]], a[floc[ptr]]);
				swap(loc[a[loc[ptr]]],loc[a[floc[ptr]]]);
				//if(DEBUG){cout<<"After:\n"; watch(ptr); watch(loc[ptr]); watch(floc[ptr]); forn(i,0,n) cout<<"loc["<<i<<"]="<<loc[i]<<'\n'; forn(i,0,n) cout<<a[i]<<" "; cout<<"\n\n"; }
				ptr++;
			}
		}
		while(ptr<n && loc[ptr]==floc[ptr]) ptr++;
		if(ptr==n){
			//if(DEBUG) cout<<"PASSED\n";
			ans=mid+1;
			for(int i=0;i<=mid;i++) P[i]=p[i], Q[i]=q[i];
			R=mid-1;
		}
		else L=mid+1;
	}
	
	return ans;
}

int main()
{
	int N, M;
	
	cin >> N;
	int S[N];
	for(int i = 0; i < N; ++i)
		cin >> S[i];
	
	cin >> M;
	int X[M], Y[M];
	for(int i = 0; i < M; ++i)
		cin >> X[i] >> Y[i];
	
	
	int P[M], Q[M];
	
	int ans = findSwapPairs(N, S, M, X, Y, P, Q);
	printf("%d\n", ans);
	for (int i = 0; i < ans; ++i)
		printf("%d %d\n", P[i], Q[i]);
	return 0;
}

Compilation message (stderr)

/tmp/ccHJqsTj.o: In function `main':
grader.c:(.text.startup+0x0): multiple definition of `main'
/tmp/cc4rWMvd.o:sorting.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status