hdu-1698-Just a Hook(线段树-区间修改模版)

http://www.notonlysuccess.com/index.php/segment-tree-complete/

#include <cstdio>
#include <algorithm>
using namespace std;
 
#define lson l , m , rt << 1
#define rson m + 1 , r , rt << 1 | 1
const int maxn = 111111;
int h , w , n;
int col[maxn<<2];
int sum[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 l,int r,int rt) {
    col[rt] = 0;
    sum[rt] = 1;
    if (l == r) return ;
    int m = (l + r) >> 1;
    build(lson);
    build(rson);
    PushUp(rt);
}
void update(int L,int R,int c,int l,int r,int rt) {
    if (L <= l && r <= R) {
        col[rt] = c;
        sum[rt] = c * (r - l + 1);
        return ;
    }
    PushDown(rt , r - l + 1);
    int m = (l + r) >> 1;
    if (L <= m) update(L , R , c , lson);
    if (R > m) update(L , R , c , rson);
    PushUp(rt);
}
int main() {
    int T , n , m;
    scanf("%d",&T);
    for (int cas = 1 ; cas <= T ; cas ++) {
        scanf("%d%d",&n,&m);
        build(1 , n , 1);
        while (m --) {
            int a , b , c;
            scanf("%d%d%d",&a,&b,&c);
            update(a , b , c , 1 , n , 1);
        }
        printf("Case %d: The total value of the hook is %d.\n",cas , sum[1]);
    }
    return 0;
}