HDU2688 Rotate

　　用树状数组求逆序对数。。。

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <iostream>
#define MAX 3000005
#define MaxN 10005

using namespace std;

int ans[MAX];
__int64 c[MaxN];

inline void updata( int s )
{
    while( s < MaxN )
    {
        c[s]++;
        s += ( s & (-s) );
    }
}

inline __int64 getsum( int s )
{
    __int64 sum = 0;
    while( s >= 1 )
    {
        sum += c[s];
        s -= s & -s;
    }   
    return sum; 
}

inline void getint( int &t ) 
{ 
    char c; 
    while( c= getchar(), c< '0'|| c> '9' ) ; 
    t= c- '0'; 
    while( c= getchar(), c>= '0'&& c<= '9' ) 
    { 
        t= t* 10+ c- '0'; 
    } 
}

int main()
{
    int N, M;
    char op[5];
    while( scanf( "%d", &N ) == 1 )
    {
        __int64 sum = 0;
        memset( c, 0, sizeof( c ) );
        for( int i = 0; i < N; ++i )
        {
            getint( ans[i] );
            updata( ans[i]+1 );
            sum += getsum( ans[i] );
        }
        scanf( "%d", &M );
        while( M-- )
        {
            scanf( "%s", op );
            switch( op[0] )
            {
                case 'Q':
                {
                    printf( "%I64d\n", sum );
                    break;        
                }
                case 'R':
                {
                    int s, e, v;
                    scanf( "%d %d", &s, &e );
                    v = ans[s];
                    for( int i = s; i < e; ++i )
                    {
                        ans[i] = ans[i+1];
                        if( v < ans[i] )
                            sum--;
                        if( v > ans[i] )
                            sum++;
                    }
                    ans[e] = v;
                    break;
                }
            }
            
        }
    }
    return 0;
}