Submission #6374072

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Source Code Expand

//Relive your past life.
//Face your demons.
//The past is never dead,it is not even past.
//The memories are not only the key to the past but...also to the future.
//coded in Rusty Lake
#include<cmath>
#include<math.h>
#include<ctype.h>
#include<algorithm>
#include<bitset>
#include<cassert>
#include<cctype>
#include<cerrno>
#include<cfloat>
#include<ciso646>
#include<climits>
#include<clocale>
#include<complex>
#include<csetjmp>
#include<csignal>
#include<cstdarg>
#include<cstddef>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<cwchar>
#include<cwctype>
#include<deque>
#include<exception>
#include<fstream>
#include<functional>
#include<iomanip>
#include<ios>
#include<iosfwd>
#include<iostream>
#include<istream>
#include<iterator>
#include<limits>
#include<list>
#include<locale>
#include<map>
#include<memory>
#include<new>
#include<numeric>
#include<ostream>
#include<queue>
#include<set>
#include<sstream>
#include<stack>
#include<stdexcept>
#include<streambuf>
#include<string>
#include<typeinfo>
#include<utility>
#include<valarray>
#include<vector>
#include<string.h>
#include<stdlib.h>
#include<stdio.h>
#define ll   long long
#define pb   push_back
#define mp   make_pair
#define orz  1000000007
using namespace std;
int n,m,u[100005],U[100005];
vector<int> v[100005],e[100005];
void dfs(int x){
    U[x]=1;
    for(int i=0;i<v[x].size();++i){
        int z=v[x][i];
        if(U[z]) continue;
        dfs(z);
    }
    int cnt=0;
    for(int i=0;i<e[x].size();++i)if(u[e[x][i]]!=1)++cnt;
    if(cnt&1)--cnt;
    for(int i=0;i<e[x].size();++i){
        if(u[e[x][i]]==2){
            u[e[x][i]]=1;
            --cnt;
            printf("%d %d\n",x,v[x][i]);
        }
    }
    for(int i=0;i<e[x].size();++i){
        if(u[e[x][i]]==0&&cnt){
            u[e[x][i]]=1;
            --cnt;
            printf("%d %d\n",x,v[x][i]);
            continue;
        }
        u[e[x][i]]=2;
    }
}
int main(){
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;++i){
        int x,y;
        scanf("%d%d",&x,&y);
        v[x].pb(y),v[y].pb(x);
        e[x].pb(i),e[y].pb(i);
    }
    if(m&1){
        puts("-1");
        return 0;
    }
    dfs(1);
    //system("pause");
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:96:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
                        ^
./Main.cpp:99:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&x,&y);
                            ^

Judge Result