ZOJ 3606 Lazy Salesgirl ( 线段树 + 思路 )

卖切糕的小女孩

http://www.cnblogs.com/wuyiqi/archive/2012/04/28/2474672.html

#include <cstdio>
#include <cstring>
#include <algorithm>

#define lson l, m, rt << 1
#define rson m+1, r, rt << 1 | 1
#define lc rt << 1
#define rc rt << 1 | 1
#define LL long long int

using namespace std;

const int MAXN = 100100;
const double INF = 1e100;
const double eps = 1e-9;

struct node
{
    int p;
    int t;
    int id;
};

int N;
int cnt[MAXN << 2];
LL sum[3][MAXN << 2];
node D1[MAXN], D2[MAXN];

bool cmp( const node& a, const node& b )
{
    return a.t < b.t;
}

void build( int l, int r, int rt )
{
    cnt[rt]=0;
    for ( int i = 0; i < 3; ++i ) sum[i][rt] = 0;
    if ( l == r ) return;
    int m = ( l + r ) >> 1;
    build( lson );
    build( rson );
    return;
}

void PushUp( int rt )
{
    cnt[rt] = cnt[lc] + cnt[rc];
    for ( int i = 0; i < 3; ++i )
        sum[i][rt] = sum[i][lc] + sum[ (i+cnt[lc])%3 ][rc];
    return;
}

void update( int L, int l, int r, int rt )
{
    if ( l == r && L == l )
    {
        ++cnt[rt];
        for ( int i = 0; i < 3; ++i )
            sum[i][rt] += (LL)D1[L].p * (i + 1);
        return;
    }

    int m = ( l + r ) >> 1;
    if ( L <= m ) update( L, lson );
    else update( L, rson );
    PushUp( rt );
    return;
}

void init()
{
    scanf( "%d", &N );
    build( 1, N, 1 );
    for ( int i = 1; i <= N; ++i )
        scanf( "%d", &D1[i].p );
    for ( int i = 1; i <= N; ++i )
        scanf( "%d", &D1[i].t );

    sort( D1 + 1, D1 + N + 1, cmp );

    D2[0].t = 0;
    for ( int i = 1; i <= N; ++i )
    {
        D2[i].id = i;
        D2[i].t = D1[i].t - D1[i - 1].t;
    }
    sort( D2 + 1, D2 + N + 1, cmp );
    return;
}

void solved()
{
    double minW;
    double maxAve = 0.0;
    int i = 1, j = 1;
    while ( i <= N )
    {
        while ( j <= N && D2[i].t == D2[j].t )
        {
            update( D2[j].id, 1, N, 1 );
            ++j;
        }

        double tmpW = (double)D2[i].t;
        double tmpA = (double)sum[0][1]/cnt[1];
        //printf( "tmp: %f %f
", tmpW, tmpA );

        if ( tmpA > maxAve )
        {
            maxAve = tmpA;
            minW = tmpW;
        }
        else if ( tmpA == maxAve )
        {
            if ( minW > tmpW )
                minW = tmpW;
        }
        i = j;
    }
    printf( "%.6f %.6f
", minW, maxAve );
    return;
}

int main()
{
    int T;
    scanf( "%d", &T );
    while (T--)
    {
        init();
        solved();
    }
    return 0;
}