自认为自己写的最美的线段树模板

  1 #include<bits/stdc++.h>
  2 using namespace std;
  3 const int MAX = 100005;
  4 typedef struct Node{
  5     long long val, tag;
  6     int l, r;
  7     Node *rson, *lson;
  8     int len() {return r - l;}
  9     int mid() {return (l + r) >> 1;}
 10     Node(): rson(NULL), lson(NULL), l(0), r(0), val(0), tag(0){}
 11 }node, *pointer;
 12 
 13 class Segment_Tree
 14 {
 15     public:
 16         pointer rt = new Node();
 17         long long a[MAX];
 18     
 19     void PushUp(pointer rt)
 20         {
 21             rt->val = rt->rson->val + rt->lson->val;
 22         }
 23     
 24     void PushDown(pointer rt)
 25         {
 26             if(rt->tag)
 27                 {
 28                     rt->lson->tag += rt->tag;
 29                     rt->rson->tag += rt->tag;
 30                     rt->lson->val += rt->tag * rt->lson->len();
 31                     rt->rson->val += rt->tag * rt->rson->len();
 32                     rt->tag = 0;
 33                 }
 34         }
 35     
 36     void Build(pointer rt,int l, int r)
 37         {
 38             rt->l = l;
 39             rt->r = r;
 40             if(l + 1 == r)
 41                 {
 42                     rt->val = a[l];
 43                     //rt->pos = l;
 44                     rt->rson = NULL;
 45                     rt->lson = NULL;
 46                     return ;
 47                 }
 48             rt->rson = new Node();
 49             rt->lson = new Node();
 50             Build(rt->lson, l, rt->mid());
 51             Build(rt->rson, rt->mid(), r);
 52             PushUp(rt); 
 53         }
 54         
 55     void UpData(pointer rt, int L, int R, int k)
 56         {
 57             if(L <= rt->l && rt->r <= R)
 58                 {
 59                     rt->val += k * rt->len();
 60                     rt->tag += k;
 61                 }
 62             else
 63                 {
 64                     if(rt->tag != 0)    PushDown(rt);
 65                     if(L < rt->mid())    UpData(rt->lson, L, R, k);
 66                     if(R > rt->mid())     UpData(rt->rson, L, R, k);
 67                     PushUp(rt);
 68                 }
 69         }
 70         
 71         long long Query(pointer rt, int L, int R)
 72             {
 73                 if(L <= rt->l && rt->r <= R)    return rt->val;
 74                 else
 75                     {
 76                         if(rt->tag != 0)    PushDown(rt);
 77                         long long ret = 0;
 78                         if(L < rt->mid())    ret += Query(rt->lson, L, R);
 79                         if(R > rt->mid()) ret += Query(rt->rson, L, R);
 80                         return ret;
 81                     }
 82             }
 83 };
 84 
 85 int main()
 86 {
 87     int n, m;
 88     int x, y, z, ord;
 89     Segment_Tree tree;
 90     scanf("%d%d", &n, &m);
 91     for(int i = 1; i <= n; i ++) scanf("%lld", &tree.a[i]);
 92     tree.Build(tree.rt, 1, n + 1);
 93     for(int i = 1; i <= m; i ++)
 94         {
 95             scanf("%d", &ord);
 96             if(ord == 1)
 97                 {
 98                     scanf("%d%d%d", &x, &y, &z);
 99                     tree.UpData(tree.rt, x, y + 1, z);
100                 }
101             if(ord ==2)
102                 {
103                     scanf("%d%d", &x, &y);
104                     printf("%lld
", tree.Query(tree.rt, x, y + 1));
105                 }
106         }
107     return 0;
108 }