Segment tree template - update interval interval sum +

Topic links:

http://poj.org/problem?id=3468

Code:

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #define LL long long
 5 using namespace std;
 6 const int maxn=100000+20;
 7 LL tree[maxn<<2];
 8 LL lazy[maxn<<2];
 9 void pushup(int rt)
10 {
11     tree[rt]=tree[rt<<1]+tree[rt<<1|1];
12 }
13 void build(int l,int r,int rt)
14 {
15     if(l==r)
16     {
17         scanf("%lld",&tree[rt]);
18         return ;
19     }
20     int m=(l+r)>>1;
21     build(l,m,rt<<1);
22     build(m+1,r,rt<<1|1);
23     pushup(rt);
24 }
25 void pushdown(int rt,int ln,int rn)
26 {
27     if(lazy[rt])
28     {
29         lazy[rt<<1]+=lazy[rt];
30         lazy[rt<<1|1]+=lazy[rt];
31         tree[rt<<1]+=lazy[rt]*ln;
32         tree[rt<<1|1]+=lazy[rt]*rn;
33         lazy[rt]=0;
34     }
35 }
36 void update(int L,int R,int C,int l,int r,int rt)
37 {
38     if( L<=l  && r <= R)
39     {
40         tree[rt]+=C*(r-l+1);
41         lazy[rt]+=C;
42         return ;
43     }
44     LL m=(l+r)>>1;
45     pushdown(rt,m-l+1,r-m);
46     if(L <= m)
47         update(L,R,C,l,m,rt<<1);
48     if(R >  m)
49         update(L,R,C,m+1,r,rt<<1|1);
50     pushup(rt);
51 }
52 LL query(int L,int R,int l,int r,int rt)
53 {
54     if(L <= l && r <= R)
55     {
56         return tree[rt];
57     }
58     int= m (L + R & lt) >> . 1 ;
 59      pushdown (RT, m-L + . 1 , RM);     // before recursion must first index the lazy down 
60      LL ANS = 0 ;
 61 is      IF (L <= m )
 62 is          ANS + = Query (L, R & lt, L, m, RT << . 1 );
 63 is      IF (R & lt> m)
 64          ANS + = Query (L, R & lt, m + . 1 , R & lt, RT << . 1 | . 1 );
 65      return ANS;
 66  }
 67  int main ()
 68  {
 69      int n-, m;
 70     cin>>n>>m;
71     build(1,n,1);
72     memset(lazy,0,sizeof(lazy));
73     char ch[20];
74     int a,b,c;
75     while(m--)
76     {
77         scanf("%s",ch);
78         if(ch[0]=='Q')
79         {
80             scanf("%d%d",&a,&b);
81             cout<<query(a,b,1,n,1)<<endl;
82         }
83         else
84         {
85             scanf("%d%d%d",&a,&b,&c);
86             update(a,b,c,1,n,1);
87         }
88     }
89 }