hdu 1166 线段树 单点更新 区间查询

很久没写线段树了,这段时间打算刷个线段树专题。这道题应该算是线段树的模版题了。

 1 #include<iostream>
 2 #define MAX_N 50005
 3 
 4 using namespace std;
 5 
 6 struct node
 7 {
 8     int peo;
 9     int l,r;
10 }num[MAX_N*4];
11 int pp[MAX_N];
12 
13 void built_tree(int l,int r,int count)
14 {
15     num[count].l=l;
16     num[count].r=r;
17     if(l==r)
18     {
19         num[count].peo = pp[l];
20         return ;
21     }
22     int mid = (l+r)/2;
23     built_tree(l, mid, count*2);
24     built_tree(mid+1, r, count*2+1);
25     num[count].peo=num[count*2].peo+num[count*2+1].peo;
26 }
27 int query_peo(int l,int r,int count)
28 {
29     if(num[count].l==l && num[count].r==r)
30         return num[count].peo;
31     int mid = (num[count].l+num[count].r)/2;
32     if(r<=mid)
33         return query_peo(l,r, count*2);
34     else
35         if(l>mid)
36             return query_peo(l, r, count*2+1);
37     else
38         return query_peo(l, mid,count*2)+query_peo(mid+1, r, count*2+1);
39 }
40  
41 void update_peo(int a,int b,int count)
42 {
43     if(num[count].l==num[count].r && num[count].l==a)
44     {
45         num[count].peo+=b;
46         return ;
47     }
48     int mid = (num[count].l+num[count].r)/2;
49     if(a<=mid)
50         update_peo(a, b, count*2);
51     else
52         if(a>mid)
53             update_peo(a, b, count*2+1);
54     num[count].peo=num[count*2].peo+num[count*2+1].peo;
55 }
56 int main()
57 {
58     cin.sync_with_stdio(false);
59     int t,con=1;
60     cin>>t;
61     while(t--)
62     {
63         int n;
64         cin>>n;
65         for(int i = 1; i <= n; i++)
66         {
67             cin>>pp[i];
68         }
69         built_tree(1, n, 1);
70         string s;
71         int a,b;
72         cout<<"Case "<<con++<<":"<<endl;
73         while(1)
74         {
75             cin>>s;
76             if(s=="End")
77                 break;
78             cin>>a>>b;
79             if(s=="Query")
80             {
81                 cout<<query_peo(a, b, 1)<<endl;
82             }
83             else
84                 if(s=="Add")
85                 {
86                     update_peo(a, b, 1);
87                 }
88             else
89                 if(s=="Sub")
90                 {
91                     b*=-1;
92                     update_peo(a, b, 1);
93                 }
94         }
95     }
96     return 0;
97 }

 

posted @ 2017-08-08 18:27  Xycdada  阅读(122)  评论(0编辑  收藏  举报