hdu 5316 Magician 线段树

2015 Multi-University Training Contest 3  1001

#include "bits/stdc++.h"
using namespace std;
#define M 100010
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1

int T, n, m;
int ans[M];
struct Node
{
    int l, r;
    long long sum11, sum12, sum21, sum22;
}node[M<<2], query_node;
const long long INF = 100000000000000 + 1;

bool First;

inline void PushPlus(int rt)
{
    node[rt].sum11 = max(node[rt<<1].sum11 + node[rt<<1|1].sum21, node[rt<<1].sum12 + node[rt<<1|1].sum11);
    node[rt].sum12 = max(node[rt<<1].sum11 + node[rt<<1|1].sum22, node[rt<<1].sum12 + node[rt<<1|1].sum12);
    node[rt].sum21 = max(node[rt<<1].sum21 + node[rt<<1|1].sum21, node[rt<<1].sum22 + node[rt<<1|1].sum11);
    node[rt].sum22 = max(node[rt<<1].sum21 + node[rt<<1|1].sum22, node[rt<<1].sum22 + node[rt<<1|1].sum12);

    node[rt].sum11 = max(node[rt].sum11, node[rt<<1|1].sum11);
    node[rt].sum12 = max(node[rt].sum12, node[rt<<1|1].sum12);
    node[rt].sum21 = max(node[rt].sum21, node[rt<<1|1].sum21);
    node[rt].sum22 = max(node[rt].sum22, node[rt<<1|1].sum22);

    node[rt].sum11 = max(node[rt].sum11, node[rt<<1].sum11);
    node[rt].sum12 = max(node[rt].sum12, node[rt<<1].sum12);
    node[rt].sum21 = max(node[rt].sum21, node[rt<<1].sum21);
    node[rt].sum22 = max(node[rt].sum22, node[rt<<1].sum22);
}


void Merge_Node(Node &newNode, Node lNode, Node rNode)
{
    newNode.sum11 = max(lNode.sum11 + rNode.sum21, lNode.sum12 + rNode.sum11);
    newNode.sum12 = max(lNode.sum11 + rNode.sum22, lNode.sum12 + rNode.sum12);
    newNode.sum21 = max(lNode.sum21 + rNode.sum21, lNode.sum22 + rNode.sum11);
    newNode.sum22 = max(lNode.sum21 + rNode.sum22, lNode.sum22 + rNode.sum12);

    newNode.sum11 = max(newNode.sum11, rNode.sum11);
    newNode.sum12 = max(newNode.sum12, rNode.sum12);
    newNode.sum21 = max(newNode.sum21, rNode.sum21);
    newNode.sum22 = max(newNode.sum22, rNode.sum22);

    newNode.sum11 = max(newNode.sum11, lNode.sum11);
    newNode.sum12 = max(newNode.sum12, lNode.sum12);
    newNode.sum21 = max(newNode.sum21, lNode.sum21);
    newNode.sum22 = max(newNode.sum22, lNode.sum22);
}

void Build(int l, int r, int rt)
{
    if(l == r) {
        scanf("%d", &ans[l]);
        node[rt].sum11 = node[rt].sum12 = node[rt].sum21 = node[rt].sum22 = -INF;
        if(l & 1) {
            node[rt].sum11 = ans[l];
        }
        else {
            node[rt].sum22 = ans[l];
        }
//        printf("l == %d  r == %d  sum11 == %lld  sum12 == %lld  sum21 == %lld  sum22 == %lld
", l, r, node[rt].sum11, node[rt].sum12, node[rt].sum21, node[rt].sum22);
        return ;
    }
    int m = ( l + r )>>1;
    Build(lson);
    Build(rson);
    PushPlus(rt);
//    printf("l == %d  r == %d  sum11 == %lld  sum12 == %lld  sum21 == %lld  sum22 == %lld
", l, r, node[rt].sum11, node[rt].sum12, node[rt].sum21, node[rt].sum22);
}

void Update(int p, int newVal, int l, int r, int rt)
{
    if(l == r) {
        if(l & 1) {
            node[rt].sum11 = newVal;
        }
        else {
            node[rt].sum22 = newVal;
        }
        return ;
    }
    int m = (l + r) >> 1;
    if(p <= m)
        Update(p, newVal, lson);
    else
        Update(p, newVal, rson);
    PushPlus(rt);
}

void Query(int L,int R,int l,int r,int rt)
{
    if(L <= l && r <= R) {
//        if(First) {
//            First = 0;
//            query_node = node[rt];
//        }
//        else {
            Merge_Node(query_node, query_node, node[rt]);
//        }
        return ;
    }
    int m = (l + r) >> 1;
    if(L <= m)
        Query(L, R, lson);
    if(R > m)
        Query(L, R, rson);
}


int main()
{
    int i, cmd, L, R, POS, VAL;
    scanf("%d", &T);
    while(T--) {
        scanf("%d%d", &n, &m);
        Build(1, n, 1);
        for(i = 1; i <= m; ++i) {
            scanf("%d", &cmd);
            if(cmd == 0) {
                scanf("%d%d", &L, &R);
//                First = 1;
                query_node.sum11 = query_node.sum12 = query_node.sum21 = query_node.sum22 = -INF;
                Query(L, R, 1, n, 1);
                printf("%lld
", max( max(query_node.sum11, query_node.sum12), max(query_node.sum21, query_node.sum22) ));
            }
            else {
                scanf("%d%d", &POS, &VAL);
                Update(POS, VAL, 1, n, 1);
            }
        }
    }
}