HDU 1698 线段树

#include<iostream>#include<string>#include<cstring>#include<algorithm>#include<cstdio>#include<cmath>#include<cctype>#include<iomanip>#define Lson left,mid,rt<<1#define Rson mid+1,right,rt<<1|1#define MID  (left+right)>>1using namespace std;const int maxn=100005;int sum[maxn<<2];int col[maxn<<2];void PushUp(int rt){    sum[rt]=sum[rt<<1]+sum[rt<<1|1];}void PushDown(int rt,int m){    if(col[rt]){        col[rt<<1]=col[rt<<1|1]=col[rt];        sum[rt<<1]=( m - (m>>1) )*col[rt];        sum[rt<<1|1]=(m>>1)*col[rt];        col[rt]=0;    }}void build(int left,int right,int rt){    col[rt]=0;    sum[rt]=1;    if(left==right)return;    int mid=MID;    build(Lson);    build(Rson);    PushUp(rt);}void update(int L,int R,int V,int left,int right,int rt){    if(L<=left&&R>=right){        col[rt] = V;        sum[rt] = V * (right-left+1);        return;    }    PushDown(rt,right-left+1);    int mid = MID;    if(L<=mid) update(L,R,V,Lson);    if(R> mid) update(L,R,V,Rson);    PushUp(rt);}int main(){    int T; scanf("%d",&T);    int cas=0;    while(T--){        int n,m;        scanf("%d%d",&n,&m);        build(1,n,1);        while(m--){            int x,y,z;            scanf("%d%d%d",&x,&y,&z);            update(x,y,z,1,n,1);        }        printf("Case %d: The total value of the hook is %d.\n",++cas,sum[1]);    }    return 0;}