hdu1698(线段树的区间替换)

#include <bits/stdc++.h>
using namespace std;
#define Maxn 1001000*4
struct Node{
    int lt,rt,val;
}A[Maxn];
int j = 1;
void Build(int i,int lt,int rt){
    A[i].lt = lt;
    A[i].rt = rt;
    A[i].val = 1;
    if( lt == rt ){
        return ;
    }
    int mid = (lt+rt) >> 1;
    Build(i<<1,lt,mid);
    Build(i<<1|1,mid+1,rt);
}

void update(int i,int lt,int rt,int val){
    if( A[i].val == val ){
        return ;
    }
    if( A[i].lt == lt && A[i].rt == rt ){
        A[i].val = val;
        return ;
    }
    if( A[i].val != -1 ){
        A[i<<1].val = A[i<<1|1].val = A[i].val;
        A[i].val = -1;
    }
    if( rt <= A[i<<1].rt ){
        update(i<<1,lt,rt,val);
    }else if( lt >= A[i<<1|1].lt ){
        update(i<<1|1,lt,rt,val);
    }else{
        update(i<<1,lt,A[i<<1].rt,val);
        update(i<<1|1,A[i<<1|1].lt,rt,val);
    }
}

int find(int i){
    if( A[i].val != -1 ){
        return ( (A[i].rt-A[i].lt+1)*A[i].val);
    }else{
        return ( find(i<<1) + find(i<<1|1) );
    }
}


int main(){
    int T,N,a,b,c;
    cin >> T;
    while(T--){
        scanf("%d",&N);
        Build(1,1,N);
        int n;
        scanf("%d",&n);
        while(n--){
            scanf("%d%d%d",&a,&b,&c);
            update(1,a,b,c);
        }
        printf("Case %d: The total value of the hook is %d.\n",j++,find(1));
    }
}