Submission #48929123

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Source Code Expand

// LUOGU_RID: 141419756
#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ldb;

#define rep(i,l,r) for(int i(l);i<=(r);++i)
#define per(i,r,l) for(int i(r);i>=(l);--i)
#define eb emplace_back
#define File(filename) freopen(filename ".in","r",stdin),freopen(filename ".out","w",stdout)

#ifdef EXODUS
	#define Debug(...) fprintf(stderr,__VA_ARGS__)
#else
	#define Debug(...) 0
#endif

//=========================================================================================================
// Something about IO

template<typename T>
void read(T &x){
	x=0;T flg=1;
	char ch=getchar();
	while(!isdigit(ch)){if(ch=='-')flg=-1;ch=getchar();}
	while(isdigit(ch))x=(x<<3)+(x<<1)+(ch^48),ch=getchar();
	x*=flg;
}
template<typename T,typename... Args>
void read(T &x,Args &...args){read(x),read(args...);}

//=========================================================================================================
// Define the global variables here.

bool membg=0;
constexpr int N=1e3+7;
int n;
int a[N];
bool memed=0;

//=========================================================================================================
// Code here.

void solve(){
	read(n);
	for(int i=1;i<=n;i++)read(a[i]);
	int icnt=0;
	for(int i=1;i<=n;i++)
		for(int j=1;j<i;j++)
			icnt+=(a[j]>a[i]);
	if(icnt&1)return printf("No\n"),void();
	vector<pair<int,int>>ans;
	for(int i=1;i<=n-2;i++){
		if(a[n]==i)ans.eb(n-1,n-3),swap(a[n-2],a[n-1]),swap(a[n-1],a[n]);
		for(int j=1;j<=n;j++)
			if(a[j]==i){
				if(j!=i){
					for(int k=j;k>i;k--)swap(a[k],a[k-1]),swap(a[k+1],a[k]);
					ans.eb(j,i-1);
				}
				break;
			}
	}
	printf("Yes\n");
	printf("%d\n",(int)ans.size());
	for(auto [x,y]:ans)printf("%d %d\n",x,y);
	return;
}


//=========================================================================================================

int main(){
	Debug("%.3lfMB\n",fabs(&memed-&membg)/1024.0/1024.0);
	int timbg=clock();
	int T=1;
	while(T--)solve();
	int timed=clock();
	Debug("%.3lfs\n",1.0*(timed-timbg)/CLOCKS_PER_SEC);
	fflush(stdout);
	return 0;
}

Submission Info

Compile Error

Main.cpp: In function ‘int main()’:
Main.cpp:18:28: warning: statement has no effect [-Wunused-value]
   18 |         #define Debug(...) 0
      |                            ^
Main.cpp:77:9: note: in expansion of macro ‘Debug’
   77 |         Debug("%.3lfMB\n",fabs(&memed-&membg)/1024.0/1024.0);
      |         ^~~~~
Main.cpp:18:28: warning: statement has no effect [-Wunused-value]
   18 |         #define Debug(...) 0
      |                            ^
Main.cpp:82:9: note: in expansion of macro ‘Debug’
   82 |         Debug("%.3lfs\n",1.0*(timed-timbg)/CLOCKS_PER_SEC);
      |         ^~~~~
Main.cpp:78:13: warning: unused variable ‘timbg’ [-Wunused-variable]
   78 |         int timbg=clock();
      |             ^~~~~
Main.cpp:81:13: warning: unused variable ‘timed’ [-Wunused-variable]
   81 |         int timed=clock();
      |             ^~~~~

Judge Result