hdu 1698 Just a Hook

来源：互联网发布：会计师事务所知乎编辑：程序博客网时间：2024/06/07 00:18

线段树成段更新，设置延迟标记，很好的方法，想出这个方法的人确实很吊

注意细节，有些小地方错了真的很难发现~

#include<iostream>#define maxn 111111using namespace std;int n,a,b,m;struct stu{int l,r,sum,flag;};stu mapp[maxn*4];void build(int l,int r,int count){mapp[count].l=l;mapp[count].r=r;mapp[count].flag=0;if(l==r){mapp[count].sum=1;mapp[count].flag=1;return;} int mid=(l+r)/2;build(l,mid,count*2);build(mid+1,r,count*2+1);mapp[count].sum=mapp[count*2].sum+mapp[count*2+1].sum;}void pushdown(int count,int x){if(mapp[count].flag){mapp[count*2].flag=mapp[count].flag;mapp[count*2+1].flag=mapp[count].flag;mapp[count*2].sum=mapp[count].flag*((x+1)/2);mapp[count*2+1].sum=mapp[count].flag*(x/2);mapp[count].flag=0;}}void updata(int l,int r,int count){if(l>=a&&r<=b){mapp[count].sum=m*(r-l+1);mapp[count].flag=m;return ;}pushdown(count,r-l+1);int mid=(l+r)/2;if(a<=mid) updata(l,mid,count*2);if(b>=mid+1) updata(mid+1,r,count*2+1);mapp[count].sum=mapp[count*2].sum+mapp[count*2+1].sum;}int main(){cin.sync_with_stdio(false);int t;cin>>t;int casee=1;while(t--){cin>>n;build(1,n,1);int s;cin>>s;for(int i=0;i<s;i++){cin>>a>>b>>m;updata(1,n,1);}cout<<"Case "<<casee++<<": The total value of the hook is ";cout<<mapp[1].sum<<"."<<endl;}return 0;}

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