hdu 4325 Flowers

线段树+离散化

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
#define lson l , m , rt << 1
#define rson m + 1 , r , rt << 1 | 1

const int maxn = 100005;
int add[maxn<<2];
int sum[maxn<<2];
int x[maxn*3];
int li[maxn],ri[maxn];
int q[maxn];

void PushUp(int rt)
{
    sum[rt] = sum[rt<<1] + sum[rt<<1|1];
}
void PushDown(int rt)
{
    if(add[rt])
    {
        add[rt<<1] += add[rt];
        add[rt<<1|1] += add[rt];
        sum[rt<<1] += add[rt];
        sum[rt<<1|1] += add[rt];
        add[rt] = 0;
    }
}
void build(int l,int r,int rt)
{
    add[rt] = 0;
    sum[rt] = 0;
    if(l == r)return ;
    int m = (l + r) >> 1;
    build(lson);
    build(rson);
}
void update(int L,int R,int l,int r,int rt)
{
    if(L <= l && r <= R)
    {
        add[rt]++;
        sum[rt]++;
        return ;
    }
    PushDown(rt);
    int m = (l + r) >> 1;
    if(L <= m)update(L,R,lson);
    if(m < R)update(L,R,rson);
    PushUp(rt);
}
int query(int k,int l,int r,int rt)
{
    if(l == k && r == k)
    {
        return sum[rt];
    }
    PushDown(rt);
    int ret = 0;
    int m = (l + r) >> 1;
    if(k <= m)ret += query(k,lson);
    else ret += query(k,rson);
    return ret;
}
int find(int key,int n)
{
    int l = 0, r = n - 1;
    while(l <= r)
    {
        int m = (l + r) >> 1;
        if(x[m] == key)return m;
        else if(x[m] < key)l = m + 1;
        else r = m - 1;
    }
    return -1;
}
int main()
{
    #ifndef ONLINE_JUDGE
    freopen("in","r",stdin);
    #endif
    int t;
    scanf("%d",&t);
    for(int cas=1;cas<=t;cas++)
    {
        int n,m;
        int nn=0;
        scanf("%d%d",&n,&m);
        for(int i=0;i<n;i++)
        {
            scanf("%d%d",&li[i],&ri[i]);
            x[nn++] = li[i];
            x[nn++] = ri[i];
        }
        for(int i=0;i<m;i++)
        {
            scanf("%d",&q[i]);
            x[nn++]=q[i];
        }
        sort(x,x+nn);
        int num = 1;
        for(int i=1;i<nn;i++)
        {
            if(x[i] != x[i-1])x[num++] = x[i];
        }
        printf("Case #%d:\n",cas);
        build(0,num,1);
        for(int i=0;i<n;i++)
        {
            int l=find(li[i],num);
            int r=find(ri[i],num);
            update(l,r,0,num,1);
        }
        for(int i=0;i<m;i++)
        {
            int k= find(q[i],num);
            printf("%d\n",query(k , 0, num,1));
        }
    }
}