[kuangbin带你飞]专题七 线段树 E

D貌似要用离散化的思想，还不会，下次补。

#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,lazy;    void updata(long long x)    {        sum = (r-l+1)*x;  //修改        lazy=x;    }} tr[maxn*4];void push_up(int id){    tr[id].sum=tr[lid].sum+tr[rid].sum;}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].lazy=0;    if(l==r) tr[id].sum=1;    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);    }}int main(){    int m,ca,num=1;    scanf("%d",&m);    while(m--){        scanf("%d%d",&n,&ca);        build(1,1,n);        while(ca--){            int l,r,x;            scanf("%d%d%d",&l,&r,&x);            updata(1,l,r,x);        }        printf("Case %d: The total value of the hook is %d.\n",num++,query_sum(1,1,n));    }    return 0;}