Submission #315505

#	Time	Username	Problem	Language	Result	Execution time	Memory
315505		daniel920712	Cat (info1cup19_cat)	C++14	25 / 100	689 ms	14956 KiB

cat

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <vector>

using namespace std;
int all[3000005];
int where[3000005];
vector < pair < int , int > > ans;
int main()
{
    int T,x,y,ok=1,N,i,j,con=0,t,tt=0;
    scanf("%d",&T);
    while(T--)
    {
        con=0;
        t=0;
        ok=1;
        ans.clear();
        scanf("%d",&N);
        for(i=1;i<=N;i++)
        {
            scanf("%d",&all[i]);
            where[all[i]]=i;
        }
        for(i=1;i<=N/2;i++)
        {
            if(all[i]!=i)
            {
                if(N-x+1==y)
                {
                    tt++;
                    if(tt%2==0) con++;
                }
            }
        }
        for(i=1;i<=N/2;i++)
        {
            if(all[i]!=i)
            {
                x=i;
                y=where[i];
                /*if(N-x+1==y)
                {
                    if(x+1==y) break;
                    swap(all[x],all[x+1]);
                    where[all[x]]=x;
                    where[all[x+1]]=x+1;
                    ans.push_back(make_pair(x,x+1));
                    swap(all[N-x+1],all[N-x]);
                    where[all[N-x+1]]=N-x+1;
                    where[all[N-x]]=N-x;
                    i--;
                }
                else*/
                {
                    con++;
                    swap(all[x],all[y]);
                    where[all[x]]=x;
                    where[all[y]]=y;
                    ans.push_back(make_pair(x,y));
                    swap(all[N-x+1],all[N-y+1]);
                    where[all[N-x+1]]=N-x+1;
                    where[all[N-y+1]]=N-y+1;
                    if(all[N-i+1]!=N-i+1) break;
                }
            }
            else if(all[N-i+1]!=N-i+1) break;

        }
        con+=tt%2;
        for(i=1;i<=N;i++) if(all[i]!=i) ok=0;
        if(ok)
        {
            printf("%d %d\n",con,ans.size());
            for(auto i:ans) printf("%d %d\n",i.first,i.second);
        }
        else printf("-1\n");

    }
    return 0;
}

Compilation message (stderr)

cat.cpp: In function 'int main()':
cat.cpp:76:25: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wformat=]
   76 |             printf("%d %d\n",con,ans.size());
      |                        ~^        ~~~~~~~~~~
      |                         |                |
      |                         int              std::vector<std::pair<int, int> >::size_type {aka long unsigned int}
      |                        %ld
cat.cpp:13:24: warning: unused variable 'j' [-Wunused-variable]
   13 |     int T,x,y,ok=1,N,i,j,con=0,t,tt=0;
      |                        ^
cat.cpp:13:32: warning: variable 't' set but not used [-Wunused-but-set-variable]
   13 |     int T,x,y,ok=1,N,i,j,con=0,t,tt=0;
      |                                ^
cat.cpp:14:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   14 |     scanf("%d",&T);
      |     ~~~~~^~~~~~~~~
cat.cpp:21:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |         scanf("%d",&N);
      |         ~~~~~^~~~~~~~~
cat.cpp:24:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   24 |             scanf("%d",&all[i]);
      |             ~~~~~^~~~~~~~~~~~~~
cat.cpp:31:17: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   31 |                 if(N-x+1==y)
      |                 ^~
cat.cpp:31:21: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   31 |                 if(N-x+1==y)
      |                    ~^~

• Subtask 1: 0 / 15
• Subtask 2: 10 / 10
• Subtask 3: 0 / 25
• Subtask 4: 15 / 15
• Subtask 5: 0 / 35