hdu 5316 多校（3）

来源：互联网发布：mac dsd播放器编辑：程序博客网时间：2024/05/16 12:57

给你n个数 m次询问：

1.将a位置的书换成b

2.询问一段区间最大子序列的和这里最大子序列不能出现奇数下标和奇数下标相邻偶数下标和偶数下标相邻；

很明显的线段树，结构体里存4个变量：

__int64 odd_even; 最大子序列是奇数下标开头偶数下标结尾
__int64 even_odd;偶数开头奇数结尾
__int64 odd_odd;奇数开头奇数结尾
__int64 even_even; 偶数开头偶数结尾

在更新是取值情况为 odd_even=max（L（ odd_even），R ( odd_even)，L（ odd_even）+R ( odd_even)，L（odd_odd）+R（even_even））

其他三个依次类推。。。。

在查找的时候返回的是结构体变量输出是比较返回的结构体里面的四个值就行；

#include<stdio.h>#include<string.h>#include<iostream>using namespace std;#define LL(x) (x<<1)#define RR(x) ((x<<1)|1)#define INF -0x3f3f3f3fstruct node{    __int64 odd_even;    __int64 even_odd;    __int64 odd_odd;    __int64 even_even;            }tree[4*100000];__int64 num[100010];__int64 max(__int64 a,__int64 b){    return a>b?a:b;}int made(int point){    tree[point].odd_odd=max(tree[LL(point)].odd_odd,tree[RR(point)].odd_odd);    tree[point].odd_odd=max(tree[point].odd_odd,tree[LL(point)].odd_odd+tree[RR(point)].even_odd);    tree[point].odd_odd=max(tree[point].odd_odd,tree[LL(point)].odd_even+tree[RR(point)].odd_odd);        tree[point].even_even=max(tree[LL(point)].even_even,tree[RR(point)].even_even);    tree[point].even_even=max(tree[point].even_even,tree[LL(point)].even_even+tree[RR(point)].odd_even);    tree[point].even_even=max(tree[point].even_even,tree[LL(point)].even_odd+tree[RR(point)].even_even);        tree[point].odd_even=max(tree[LL(point)].odd_even,tree[RR(point)].odd_even);    tree[point].odd_even=max(tree[point].odd_even,tree[LL(point)].odd_even+tree[RR(point)].odd_even);    tree[point].odd_even=max(tree[point].odd_even,tree[LL(point)].odd_odd+tree[RR(point)].even_even);        tree[point].even_odd=max(tree[LL(point)].even_odd,tree[RR(point)].even_odd);    tree[point].even_odd=max(tree[point].even_odd,tree[LL(point)].even_odd+tree[RR(point)].even_odd);    tree[point].even_odd=max(tree[point].even_odd,tree[LL(point)].even_even+tree[RR(point)].odd_odd);        return 0;}int deal(int L,int R,int point){    if(L==R)    {        tree[point].odd_even=tree[point].even_odd=INF;        tree[point].odd_odd=tree[point].even_even=INF;        if(L%2==0) tree[point].even_even=num[L];        else tree[point].odd_odd=num[L];        return 0;    }    int mid=(L+R)/2;    deal(L,mid,LL(point));    deal(mid+1,R,RR(point));        made(point);    return 0;}int update(int L,int R,int pos,int k,int point){    if(L==R&&L==pos)    {        tree[point].odd_even=tree[point].even_odd=INF;        tree[point].odd_odd=tree[point].even_even=INF;        if(L%2==0) tree[point].even_even=k;        else tree[point].odd_odd=k;        return 0;    }        int mid=(L+R)/2;    if(pos<=mid) update(L,mid,pos,k,LL(point));    else update(mid+1,R,pos,k,RR(point));    made(point);        return 0;}struct node find(int L,int R,int left,int right,int point){    if(L==left&&R==right)    {        return tree[point];    }        int mid=(L+R)/2;    if(right<=mid)    {        return find(L,mid,left,right,LL(point));    }    else if(left>mid)     {        return find(mid+1,R,left,right,RR(point));    }    else    {        node a=find(L,mid,left,mid,LL(point));        node b=find(mid+1,R,mid+1,right,RR(point));        node c;        c.odd_odd=max(a.odd_odd,b.odd_odd);        c.odd_odd=max(c.odd_odd,a.odd_odd+b.even_odd);        c.odd_odd=max(c.odd_odd,a.odd_even+b.odd_odd);                c.even_even=max(a.even_even,b.even_even);        c.even_even=max(c.even_even,a.even_even+b.odd_even);        c.even_even=max(c.even_even,a.even_odd+b.even_even);            c.odd_even=max(a.odd_even,b.odd_even);        c.odd_even=max(c.odd_even,a.odd_even+b.odd_even);        c.odd_even=max(c.odd_even,a.odd_odd+b.even_even);            c.even_odd=max(a.even_odd,b.even_odd);        c.even_odd=max(c.even_odd,a.even_odd+b.even_odd);        c.even_odd=max(c.even_odd,a.even_even+b.odd_odd);        return c;    }    }int main(){    int n,m,T,i,j;    scanf("%d",&T);        while(T--)    {        scanf("%d%d",&n,&m);        deal(1,n,1);        for(i=1;i<=n;i++)        {            scanf("%I64d",&num[i]);        }                deal(1,n,1);        while(m--)        {            int a,b,c;            scanf("%d%d%d",&a,&b,&c);            if(a==0)            {                node p=find(1,n,b,c,1);                __int64 Max;                Max=max(p.odd_even,p.even_odd);                Max=max(Max,p.odd_odd);                Max=max(Max,p.even_even);                printf("%I64d\n",Max);            }            else            {                update(1,n,b,c,1);            }        }    }    return 0;    }

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