UESTC-1057 秋实大哥与花 （区间修改，区间求和）

https://vjudge.net/problem/UESTC-1057

区间修改，一个个改复杂度是nlogn还不如暴力，这里用到线段树的lazy思想，保证复杂度为logn

#include <iostream>#include <cstdio>#include <cstring>#define lid (id << 1)#define rid (id << 1 | 1)using namespace std;const int maxn = 1e5+6;int n,a[maxn],q;struct node{    int l,r;    long long sum,Max,lazy;    void updata(long long x)    {        sum =sum+(r-l+1)*x; //增加        Max=Max+x;        lazy=lazy+x;       /* sum = (r-l+1)*x;  //修改          Max=x;          lazy=x; */    }} tr[maxn*4];void push_up(int id){    tr[id].sum=tr[lid].sum+tr[rid].sum;    tr[id].Max = max(tr[lid].Max,tr[rid].Max);}void push_down(int id){    int lazyvalue=tr[id].lazy;    if(lazyvalue)    {        tr[lid].updata(lazyvalue);        tr[rid].updata(lazyvalue);        tr[id].lazy=0;    }}void build(int id,int l,int r){    tr[id].l=l,tr[id].r=r;    tr[id].sum=0,tr[id].Max=0,tr[id].lazy=0;    if(l==r) tr[id].sum=a[l],tr[id].Max=a[l];    else    {        int mid=(l+r)/2;        build(lid,l,mid);        build(rid,mid+1,r);        push_up(id);    }}void updata(int id,int l,int r,long long val){    if(l==tr[id].l&&tr[id].r==r) tr[id].updata(val);    else    {        push_down(id);        int mid = (tr[id].l+tr[id].r)>>1;        if(r<=mid) updata(lid,l,r,val);        else if (l>mid) updata(rid,l,r,val);        else        {            updata(lid,l,mid,val);            updata(rid,mid+1,r,val);        }        push_up(id);    }}long long query_sum(int id,int l,int r){    if(l==tr[id].l&&tr[id].r==r) return tr[id].sum;    else    {        push_down(id);        int mid = (tr[id].l+tr[id].r)/2;        if(r<=mid)  return query_sum(lid,l,r);        else if(l>mid) return query_sum(rid,l,r);        else return query_sum(lid,l,mid)+query_sum(rid,mid+1,r);        push_up(id);    }}long long query_max(int id,int l,int r){    if(l==tr[id].l&&tr[id].r==r) return tr[id].Max;    else    {        push_down(id);        int mid = (tr[id].l+tr[id].r)/2;        if(r<=mid)  return query_max(lid,l,r);        else if(l>mid) return query_max(rid,l,r);        else return max(query_max(lid,l,mid),query_max(rid,mid+1,r));        push_up(id);    }}int main(){    scanf("%d",&n);    for(int i=1; i<=n; i++)    {        scanf("%d",&a[i]);    }    build(1,1,n);    scanf("%d",&q);    for(int i=1; i<=q; i++)    {        int l,r,val;        scanf("%d%d%d",&l,&r,&val);        updata(1,l,r,val);        printf("%lld\n",query_sum(1,l,r));    }    return 0;}