#include<stdio.h>

#include<string.h>

#include<algorithm>

using namespace std;

struct node{

    int l, r, s;

}num[800005];

int n, m, key;

void build(int l,int r,int k)

{

    num[k].l = l;

    num[k].r = r;

    num[k].s = 0;

    if(l == r)

    {

        num[k].s = 1;

        return;

    }

    int mi = (l+r)>>1;

    build(l,mi,k+k);

    build(mi+1,r,k+k+1);

    return;

}

void update(int l, int r, int k)

{

    if(num[k].s)

    {

        num[k+k].s = num[k+k+1].s = num[k].s;

        num[k].s = 0;

    }

    if(num[k].l == l && num[k].r == r)

    {

        num[k].s = key;

        return;

    }

    int mi = (num[k].l+num[k].r)>>1;

    if(l > mi)    update(l,r,k+k+1);

    else if(r <= mi)    update(l,r,k+k);

    else

    {

        update(l,mi,k+k);

        update(mi+1,r,k+k+1);

    }

    return;

}

int query(int k)

{

    if(num[k].s)    return (num[k].r-num[k].l+1)*num[k].s;

    else return query(k+k)+query(k+k+1);

}

int main()

{

    int Case;

    int a, b;

    scanf("%d",&Case);

    for(int j=1;j<=Case;j++)

    {

        memset(num,0,sizeof(num));

        scanf("%d",&n);

        build(1,n,1);

        scanf("%d",&m);

        while(m--)

        {

            scanf("%d%d%d",&a,&b,&key);

            update(a,b,1);

        }

        printf("Case %d: The total value of the hook is %d.\n",j,query(1));

    }

    return 0;

}

Code From Hdu1698