nylg 600 花儿朵朵 //离散化+树状数组或线段树

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=600

树状数组+离散化：

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;
#define maxn 300005
#define lowbit(x) (x&-x)
struct node
{
      int val, pos;
      bool operator < (const node& n)const
      {
            return val<n.val;
      }
}mm[maxn];
int real[maxn], fen[maxn];
void add(int x, int n, int d)
{
      while (x<=n)
      {
            fen[x] += d;
            x += lowbit(x);
      }
}
int sum(int x)
{
      int Sum = 0;
      while (x>0)
      {
            Sum += fen[x];
            x -= lowbit(x);
      }
      return Sum;
}
int main()
{
      int ncase, n, m, a, b, N, x;
      scanf("%d", &ncase);
      while (ncase--)
      {
            scanf("%d%d", &n, &m);
            N = n*2 + m;
            for (int i=1; i<=N; i++)
            {
                  scanf("%d", &a);
                  mm[i].val = a;//需要离散化的点
                  mm[i].pos = i;
            }
            sort(mm+1, mm+N+1);
            x = 0;
            for (int i=1; i<=N; ++i)//离散化
            {
                  if (mm[i].val != mm[i-1].val)
                        real[ mm[i].pos ] = ++x;
                  else
                        real[ mm[i].pos ] = x;
            }
            memset(fen, 0, sizeof(fen));
            for (int i=1; i<=2*n; i+=2)
            {
                  add(real[i], x+1, 1);
                  add(real[i+1]+1, x+1, -1);
            }
            for (int i=n*2+1; i<=N; ++i)
                  printf("%d\n", sum(real[i]));
      }
      return 0;
}
           

离散化+线段树：

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
#define maxn 300005
int real[maxn];
struct node
{
      int val, pos;
      bool operator < (const node& n)const
      {
            return val<n.val;
      }
}mm[maxn];
struct Node
{
      int l, r, d;
}v[maxn<<2];
void pushdown(int n)
{
      if (v[n].d)
      {
            v[n<<1].d += v[n].d;
            v[n<<1|1].d += v[n].d;
            v[n].d = 0;
      }
}
void build(int l, int r, int n)
{
      v[n].l = l, v[n].r = r, v[n].d = 0;
      if (l==r)
            return ;
      int mid = (l+r)>>1;
      build(l, mid, n<<1);
      build(mid+1, r, n<<1|1);
}
void update(int l, int r, int n, int d)
{
      if (l<=v[n].l && v[n].r<=r)
      {
            v[n].d += d;
            return ;
      }
      pushdown(n);
      int mid = (v[n].l + v[n].r) >> 1;
      if (r<=mid)
            update(l, r, n<<1, d);
      else if (l>mid)
            update(l, r, n<<1|1, d);
      else
      {
            update(l, mid, n<<1, d);
            update(mid+1, r, n<<1|1, d);
      }
}
int query(int x, int n)
{
      if (v[n].l==x && v[n].r==x)
            return v[n].d;
      pushdown(n);
      int mid = (v[n].l + v[n].r) >> 1;
      if (x<=mid)
            return query(x, n<<1);
      return query(x, n<<1|1);
}
int main()
{
      int ncase, n, m, a, b, N, x;
      scanf("%d", &ncase);
      while (ncase--)
      {
            scanf("%d%d", &n, &m);
            N = n*2 + m;
            for (int i=1; i<=N; ++i)
            {
                  scanf("%d", &a);
                  mm[i].val = a;//需要离散化的点
                  mm[i].pos = i;
            }
            sort(mm+1, mm+N+1);
            x = 0;
            for (int i=1; i<=N; ++i)//离散化
            {
                  if (mm[i].val != mm[i-1].val)
                        real[ mm[i].pos ] = ++x;
                  else
                        real[ mm[i].pos ] = x;
            }
            build(1, x, 1);
            for (int i=1; i<=2*n; i+=2)
                  update( real[i], real[i+1], 1, 1 );
            for (int i=2*n+1; i<=N; i++)
                  printf("%d\n", query( real[i], 1 ));
      }
      return 0;
}
           

hash：

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
#define N 100000
int a[N], b[N];
int main()
{
      int ncase, n, m, x, y;
      scanf("%d", &ncase);
      while (ncase--)
      {
            scanf("%d%d", &n, &m);
            memset(a, 0, sizeof(a));
            memset(b, 0,sizeof(b));
            for (int i=0; i<n; i++)
            {
                  scanf("%d%d", &x, &y);
                  if (y<=N)
                        for (int j=x; j<=y; ++j)
                              ++a[j];
                  else if (x>N)
                        for (int j=x%N, t=y%N; j<=t; ++j)
                              ++b[j];
                  else
                  {
                        for (int j=x; j<=N; ++j)
                              ++a[j];
                        for (int j=0, t=y%N; j<=t; ++j)
                              ++b[j];
                  }
            }
            while (m--)
            {
                  scanf("%d", &x);
                  if (x<=N)
                        printf("%d\n", a[x]);
                  else
                        printf("%d\n", b[y%N]);
            }
      }
      return 0;
}