Submission #844981


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// {{{ by shik
#include <bits/stdc++.h>
#include <unistd.h>
#define SZ(x) ((int)(x).size())
#define ALL(x) begin(x),end(x)
#define REP(i,n) for ( int i=0; i<int(n); i++ )
#define REP1(i,a,b) for ( int i=(a); i<=int(b); i++ )
#define FOR(it,c) for ( auto it=(c).begin(); it!=(c).end(); it++ )
#define MP make_pair
#define PB push_back
using namespace std;
typedef long long LL;
typedef pair<int,int> PII;
typedef vector<int> VI;

#ifdef SHIK
template<typename T>
void _dump( const char* s, T&& head ) { cerr<<s<<"="<<head<<endl; }

template<typename T, typename... Args>
void _dump( const char* s, T&& head, Args&&... tail ) {
    int c=0;
    while ( *s!=',' || c!=0 ) {
        if ( *s=='(' || *s=='[' || *s=='{' ) c++;
        if ( *s==')' || *s==']' || *s=='}' ) c--;
        cerr<<*s++;
    }
    cerr<<"="<<head<<", ";
    _dump(s+1,tail...);
}

#define dump(...) do { \
    fprintf(stderr, "%s:%d - ", __PRETTY_FUNCTION__, __LINE__); \
    _dump(#__VA_ARGS__, __VA_ARGS__); \
} while (0)

template<typename Iter>
ostream& _out( ostream &s, Iter b, Iter e ) {
    s<<"[";
    for ( auto it=b; it!=e; it++ ) s<<(it==b?"":" ")<<*it;
    s<<"]";
    return s;
}

template<typename A, typename B>
ostream& operator <<( ostream &s, const pair<A,B> &p ) { return s<<"("<<p.first<<","<<p.second<<")"; }
template<typename T>
ostream& operator <<( ostream &s, const vector<T> &c ) { return _out(s,ALL(c)); }
template<typename T, size_t N>
ostream& operator <<( ostream &s, const array<T,N> &c ) { return _out(s,ALL(c)); }
template<typename T>
ostream& operator <<( ostream &s, const set<T> &c ) { return _out(s,ALL(c)); }
template<typename A, typename B>
ostream& operator <<( ostream &s, const map<A,B> &c ) { return _out(s,ALL(c)); }
#else
#define dump(...)
#endif

template<typename T>
void _R( T &x ) { cin>>x; }
void _R( int &x ) { scanf("%d",&x); }
void _R( long long &x ) { scanf("%" PRId64,&x); }
void _R( double &x ) { scanf("%lf",&x); }
void _R( char &x ) { scanf(" %c",&x); }
void _R( char *x ) { scanf("%s",x); }

void R() {}
template<typename T, typename... U>
void R( T& head, U&... tail ) {
    _R(head);
    R(tail...);
}

template<typename T>
void _W( const T &x ) { cout<<x; }
void _W( const int &x ) { printf("%d",x); }
template<typename T>
void _W( const vector<T> &x ) {
    for ( auto i=x.cbegin(); i!=x.cend(); i++ ) {
        if ( i!=x.cbegin() ) putchar(' ');
        _W(*i);
    }
}

void W() {}
template<typename T, typename... U>
void W( const T& head, const U&... tail ) {
    _W(head);
    putchar(sizeof...(tail)?' ':'\n');
    W(tail...);
}

#ifdef SHIK
#define FILEIO(...)
#else
#define FILEIO(name) do {\
    freopen(name ".in","r",stdin); \
    freopen(name ".out","w",stdout); \
} while (0)
#endif

// }}}

const int N=1e5+10;
int n,a[N],b[N];

bool cmp( int x, int y ) {
    return a[x]<a[y];
}

int main() {
    R(n);
    REP(i,n) R(a[i]);
    REP(i,n) b[i]=i;
    sort(b,b+n,cmp);
    int ans=0;
    REP(i,n) if ( i%2!=b[i]%2 ) ans++;
    assert(ans%2==0);
    W(ans/2);
    return 0;
}

Submission Info

Submission Time
Task C - BBuBBBlesort!
User shik
Language C++14 (GCC 5.4.1)
Score 600
Code Size 3143 Byte
Status
Exec Time 45 ms
Memory 1024 KB

Compile Error

./Main.cpp: In function ‘void _R(long long int&)’:
./Main.cpp:62:46: warning: format ‘%ld’ expects argument of type ‘long int*’, but argument 2 has type ‘long long int*’ [-Wformat=]
 void _R( long long &x ) { scanf("%" PRId64,&x); }
                                              ^
./Main.cpp: In function ‘void _R(int&)’:
./Main.cpp:61:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
 void _R( int &x ) { scanf("%d",&x); }
                                   ^
./Main.cpp: In function ‘void _R(long long int&)’:
./Main.cpp:62:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
 void _R( long long &x ) { scanf("%" PRId64,&x); }
                                               ^
./Main.cpp: In function ‘void _R(double&)’:
./Main.cpp:63:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-resu...

Test Cases

Set Name Score / Max Score Test Cases
Sample 0 / 0 s1.txt, s2.txt
All 600 / 600 01.txt, 02.txt, 03.txt, 04.txt, 05.txt, 06.txt, 07.txt, 08.txt, 09.txt, 10.txt, 11.txt, 12.txt, 13.txt, 14.txt, 15.txt, 16.txt, 17.txt, 18.txt, 19.txt, 20.txt, 21.txt, 22.txt, s1.txt, s2.txt
Case Name Status Exec Time Memory
01.txt 44 ms 1024 KB
02.txt 45 ms 1024 KB
03.txt 45 ms 1024 KB
04.txt 45 ms 1024 KB
05.txt 40 ms 1024 KB
06.txt 40 ms 1024 KB
07.txt 40 ms 1024 KB
08.txt 29 ms 1024 KB
09.txt 29 ms 1024 KB
10.txt 26 ms 1024 KB
11.txt 26 ms 1024 KB
12.txt 28 ms 1024 KB
13.txt 28 ms 1024 KB
14.txt 40 ms 1024 KB
15.txt 44 ms 1024 KB
16.txt 41 ms 1024 KB
17.txt 40 ms 1024 KB
18.txt 4 ms 256 KB
19.txt 5 ms 256 KB
20.txt 4 ms 256 KB
21.txt 4 ms 256 KB
22.txt 4 ms 256 KB
s1.txt 4 ms 256 KB
s2.txt 4 ms 256 KB