线段树板子C++

  1     struct node
  2     {
  3         int l,r,sum,lazy;
  4         node *lson,*rson;
  5         node()
  6         {
  7             l = r = sum = lazy = 0;
  8             lson = rson = NULL;
  9         }
 10     };
 11 
 12     node* build(vector<int> &v,int l,int r)
 13     {
 14         node *k = new node;
 15         k->l = l;
 16         k->r = r;
 17 
 18         if(l == r)
 19         {
 20             k->sum = v[l];
 21             return k;
 22         }
 23 
 24         int mid = (l+r)/2;
 25         k->lson = build(v,l,mid);
 26         k->rson = build(v,mid+1,r);
 27         update(k);
 28 
 29         return k;
 30     }
 31 
 32     void update(node* k)
 33     {
 34         k->sum = 0;
 35 
 36         if(k->lson)
 37             k->sum += k->lson->sum;
 38         if(k->rson)
 39             k->sum += k->rson->sum;
 40     }
 41 
 42     //同范围加上一个相同的数
 43     void changeSegment(node *k,int l,int r)
 44     {
 45         if(k->lazy)
 46             pushdown(k);
 47 
 48         if(k->l==l && k->r==r)
 49         {
 50             k->sum = (r-l+1)-k->sum;
 51             k->lazy = (k->lazy+1)%2;
 52             return;
 53         }
 54 
 55         int mid = (k->l+k->r)/2;
 56 
 57         if(r <= mid)
 58             changeSegment(k->lson,l,r);
 59         else if(l > mid)
 60             changeSegment(k->rson,l,r);
 61         else
 62         {
 63             changeSegment(k->lson,l,mid);
 64             changeSegment(k->rson,mid+1,r);
 65         }
 66 
 67         update(k);
 68     }
 69 
 70     void pushdown(node *k)
 71     {
 72         if(k->l == k->r)
 73         {
 74             k->lazy = 0;
 75             return;
 76         }
 77 
 78         if(k->lazy)
 79             k->lson->sum = (k->lson->r-k->lson->l+1) - k->lson->sum;
 80         if(k->lazy)
 81             k->rson->sum = (k->rson->r-k->rson->l+1) - k->rson->sum;
 82 
 83         k->lson->lazy = (k->lson->lazy + k->lazy)%2;
 84         k->rson->lazy = (k->rson->lazy + k->lazy)%2;
 85 
 86         k->lazy = 0;
 87     }
 88 
 89     int query(node *k,int l,int r)
 90     {   
 91         if(k->lazy)
 92             pushdown(k);
 93             
 94         if(k->l==l && k->r==r)
 95             return k->sum;
 96         
 97         int mid = (k->l+k->r)/2;
 98 
 99         if(r <= mid)
100             return query(k->lson,l,r);
101         else if(l > mid)
102             return query(k->rson,l,r);
103         else
104             return query(k->lson,l,mid)+query(k->rson,mid+1,r);
105     }
posted on 2023-02-20 15:06 么么打123 阅读(27) 评论(0) 收藏举报