hdu 4217

想了很久，才知道用线段树来做，实现也不算太复杂。

#include<iostream>

#include<cstdio>

#include<cstring>

using namespace std;

#define SIZE 262145

struct node

{

    int i,left,right,sum;

};

node vert[SIZE<<2];

int treeNode;

int build(int i,int left,int right)

{

    int mid;

    vert[i].left=left;

    vert[i].right=right;

    vert[i].sum=right-left+1;

    if(left==right)

    {

        vert[i].i=++treeNode;

        return 0;

    }



    mid=(left+right)>>1;

    build(i<<1,left,mid);

    build((i<<1)+1,mid+1,right);



    return 0;

}

int query(int i,int n,int goal)

{

    int res;

    if(vert[i].left==vert[i].right)

    {

        vert[i].sum=0;

        return vert[i].i;

    }



    if(goal <= vert[i<<1].sum)  

    {

        res = query(i<<1,n,goal);

    }

    else

    {

        res = query((i<<1)+1,n,goal-vert[i<<1].sum);

    }

    vert[i].sum--;

    return res;

}

int main()

{

    int i,k,m,n,inum,count=0;

    __int64 sum;

    scanf("%d",&inum);

    while(inum--)

    {

        count++; sum=0; treeNode=0;

        scanf("%d %d",&n,&m);

        build(1,1,n);

        for(i=0;i<m;i++)

        {

            scanf("%d",&k);

            sum+=query(1,n,k);

        }

        printf("Case %d: %I64d\n",count,sum);

    }

    return 0;

}