线段树(成段更新) HDU 1698 Just a Hook

题目传送门

  1 /*
  2     线段树-成段更新：第一题！只要更新区间，输出总长度就行了
  3     虽然是超级裸题，但是用自己的风格写出来，还是很开心的:)
  4 */
  5 #include <cstdio>
  6 #include <algorithm>
  7 #include <cmath>
  8 #include <cstring>
  9 #include <string>
 10 #include <iostream>
 11 using namespace std;
 12
 13 #define lson l, mid, rt << 1
 14 #define rson mid + 1, r, rt << 1 | 1
 15
 16 const int MAXN = 1e5 + 10;
 17 const int INF = 0x3f3f3f3f;
 18 struct Node
 19 {
 20     int v, sum, add, mx, mn, len;
 21 }node[MAXN<<2];
 22
 23 void push_up(int rt)
 24 {
 25     node[rt].sum = node[rt<<1].sum + node[rt<<1|1].sum;
 26 }
 27
 28 void push_down(int rt, int c)
 29 {
 30     if (node[rt].add)
 31     {
 32         node[rt<<1].add = node[rt<<1|1].add = node[rt].add;
 33         node[rt<<1].sum = node[rt<<1].add * (c - (c >> 1));
 34         node[rt<<1|1].sum = node[rt<<1|1].add * (c >> 1);
 35         node[rt].add = 0;
 36     }
 37 }
 38
 39 void build(int l, int r, int rt)
 40 {
 41     node[rt].add = 0;
 42     if (l == r)    {node[rt].sum = 1;        return ;}
 43     int mid = (l + r) >> 1;
 44     build (lson);    build (rson);
 45
 46     push_up (rt);
 47 }
 48
 49 void updata(int ql, int qr, int c, int l, int r, int rt)
 50 {
 51     if (ql <= l && r <= qr)    {node[rt].sum = c * (r - l + 1);    node[rt].add = c;    return ;}
 52
 53     push_down (rt, r - l + 1);
 54
 55     int mid = (l + r) >> 1;
 56     if (ql <= mid)    updata (ql, qr, c, lson);
 57     if (qr > mid)    updata (ql, qr, c, rson);
 58
 59     push_up (rt);
 60 }
 61
 62 int query(int ql, int qr, int l, int r, int rt)
 63 {
 64     if (ql <= l && r <= qr)    {return node[rt].sum;}
 65
 66     push_down (rt, r - l + 1);
 67
 68     int mid = (l + r) >> 1;        int ans = 0;
 69     if (ql <= mid)    ans = query (ql, qr, lson);
 70     if (qr > mid)    ans = query (ql, qr, rson);
 71
 72     return ans;
 73 }
 74
 75 int main(void)        //HDU 1698 Just a Hook
 76 {
 77     //freopen ("HDOJ_1698.in", "r", stdin);
 78
 79     int t, cas = 0;
 80     scanf ("%d", &t);
 81     while (t--)
 82     {
 83         int n, q;
 84         scanf ("%d", &n);
 85         build (1, n, 1);
 86
 87         scanf ("%d", &q);
 88         while (q--)
 89         {
 90             int ql, qr, c;
 91             scanf ("%d%d%d", &ql, &qr, &c);
 92             updata (ql, qr, c, 1, n, 1);
 93         }
 94
 95         printf ("Case %d: The total value of the hook is %d.\n", ++cas, node[1].sum);
 96     }
 97
 98     return 0;
 99 }
100
101 /*
102 Case 1: The total value of the hook is 24.
103 */