hdu 4614 Vases and Flowers

查询区间的空花盆数量，修改区间的空花盆数量，很容易就想到是线段树。然后用二分找到第一个和最后一个空花盆的位置。

#include <cstdio>#include <cstdlib>#include <cstring>#include <cmath>#include <cctype>#include <vector>#include <stack>#include <queue>#include <map>#include <algorithm>#include <iostream>#include <string>#include <set>#define X first#define Y second#define sqr(x) (x)*(x)using namespace std;const double PI = acos(-1.0);map<int,int>::iterator it;typedef long long LL ;#pragma comment(linker,"/STACK:102400000,102400000")const int maxn = 50005;#define lson L , mid , rt << 1#define rson mid + 1 , R , rt << 1 | 1#define lc rt<<1#define rc rt<<1|1struct Segment_Tree{    int left[maxn*4],right[maxn*4];    int sum[maxn*4];    int add[maxn*4];    bool npd[maxn*4];    void Build(int L,int R,int rt)    {        left[rt]=L,right[rt]=R;        sum[rt]=R-L+1;        add[rt]=0;        npd[rt]=false;        if(L==R)        {            ;        }        else        {            int mid = (L+R)>>1;            Build(lson);            Build(rson);            Push_Up(rt);        }    }    void Push_Up(int rt)    {        sum[rt]=sum[lc]+sum[rc];    }    void Push_Down(int rt)    {        if(npd[rt])        {            npd[lc]=npd[rc]=1;            npd[rt]=0;            sum[lc]=(right[lc]-left[lc]+1)*add[rt];            sum[rc]=(right[rc]-left[rc]+1)*add[rt];            add[lc]=add[rt];            add[rc]=add[rt];        }    }    void Update(int L,int R,int rt,int from,int to,int val)    {        if(from<=L&&R<=to)        {            add[rt]=val;            sum[rt]=(right[rt]-left[rt]+1)*val;            npd[rt]=1;        }        else        {            int mid = (L+R)>>1;            Push_Down(rt);            if(from<=mid)            {                Update(lson,from,to,val);            }            if(to>mid)            {                Update(rson,from,to,val);            }            Push_Up(rt);        }    }    int Query(int L,int R,int rt,int from,int to)    {        if(from<=L&&R<=to)        {            return sum[rt];        }        else        {            int mid = (L+R)>>1;            Push_Down(rt);            int ret=0;            if(from<=mid)            {                ret+=Query(lson,from,to);            }            if(to>mid)            {                ret+= Query(rson,from,to);            }            return ret;        }    }} Seg;int main(){    int T;    scanf("%d",&T);    while(T--)    {        int n,m;        scanf("%d%d",&n,&m);        Seg.Build(1,n,1);        while(m--)        {            int k,a,b;            scanf("%d%d%d",&k,&a,&b);            ++a;            if(k==1)            {                int l=a,r=n,mid,ans=-1;                while(l<=r)                {                    mid=(l+r)/2;                    int cnt=Seg.Query(1,n,1,a,mid);                    if(cnt>=1)                    {                        ans=mid;                        r = mid - 1;                    }                    else                    {                        l = mid + 1;                    }                }                if(~ans)                {                    int left=ans;                    l=left;                    r=n,mid,ans=-1;                    while(l<=r)                    {                        mid=(l+r)/2;                        int cnt=Seg.Query(1,n,1,left,mid);                        if(cnt>=b)                        {                            ans=mid;                            r = mid - 1;                        }                        else                        {                            l = mid + 1;                        }                    }                    if(~ans)                    {                        //printf("sum = %d b = %d\n",Seg.Query(1,n,1,left,ans),b);                        //puts("hered1");                        Seg.Update(1,n,1,left,ans,0);                        printf("%d %d\n",left-1,ans-1);                    }                    else                    {                        l=ans;                        //printf("pans = %d\n",ans);                        r=n,mid,ans=-1;                        while(l<=r)                        {                            mid=(l+r)/2;                            int cnt=Seg.Query(1,n,1,mid,n);                            if(cnt>=1)                            {                                ans=mid;                                l = mid + 1;                            }                            else                            {                                r = mid - 1;                            }                        }                        //printf("ans = %d\n",ans);                        //puts("hered2");                        Seg.Update(1,n,1,left,ans,0);                        printf("%d %d\n",left-1,ans-1);                    }                }                else                {                    puts("Can not put any one.");                }            }            else            {                if(b>n-1)b=n-1;                ++b;                int sum = Seg.Query(1,n,1,a,b);                //printf("sum empty = %d\n",sum);                sum = b-a+1-sum;                printf("%d\n",sum);                Seg.Update(1,n,1,a,b,1);            }        }        puts("");    }    return 0;}