poj 3468 A Simple Problem with Integers（线段树区间修改+区间求和）

Description

You have N integers, A1, A2, … , AN. You need to deal with two kinds of operations. One type of operation is to add some given number to each number in a given interval. The other is to ask for the sum of numbers in a given interval.

Input

The first line contains two numbers N and Q. 1 ≤ N,Q ≤ 100000.
The second line contains N numbers, the initial values of A1, A2, … , AN. -1000000000 ≤ Ai ≤ 1000000000.
Each of the next Q lines represents an operation.
“C a b c” means adding c to each of Aa, Aa+1, … , Ab. -10000 ≤ c ≤ 10000.
“Q a b” means querying the sum of Aa, Aa+1, … , Ab.

Output

You need to answer all Q commands in order. One answer in a line.

Sample Input

10 5
1 2 3 4 5 6 7 8 9 10
Q 4 4
Q 1 10
Q 2 4
C 3 6 3
Q 2 4
Sample Output

4
55
9
15
Hint

The sums may exceed the range of 32-bit integers.

代码如下

#include<iostream>#include <cstdio>  #include <algorithm>    #define lson l , m , rt << 1  #define rson m + 1 , r , rt << 1 | 1  #define LL long long  using namespace std;const int maxn =100005;  LL lazy[maxn<<2];  LL sum[maxn<<2]; int A[maxn]; void PushUp(int rt) {      sum[rt]=sum[rt<<1]+sum[rt<<1|1];  }  void PushDown(int rt,int m){      if(lazy[rt])    {          lazy[rt<<1]+=lazy[rt];          lazy[rt<<1|1]+=lazy[rt];          sum[rt<<1]+=lazy[rt]*(m-(m>>1));          sum[rt<<1|1]+=lazy[rt]*(m>>1);          lazy[rt]=0;      }  }  void build(int l,int r,int rt) {      lazy[rt] = 0;      if(l==r)     {          //scanf("%lld",&sum[rt]);         sum[rt]=A[l];         return ;      }      int m=(l+r)>>1;      build(lson);      build(rson);      PushUp(rt);  }  void update(int L,int R,int c,int l,int r,int rt) {      if (L<=l&&r<=R)     {          lazy[rt]+=c;        sum[rt]+=(LL)c*(r-l+1);          return ;      }      PushDown(rt,r-l+1);      int m=(l+r)>>1;      if (L<=m) update(L,R,c,lson);      if (m<R) update(L,R,c,rson);      PushUp(rt);  }  LL query(int L,int R,int l,int r,int rt) {      if (L<=l&&r<=R)     {          return sum[rt];      }      PushDown(rt,r-l+1);      int m=(l+r)>>1;      LL ret = 0;      if (L<=m) ret+=query(L,R,lson);      if (m<R) ret+=query(L,R,rson);      return ret;  }  int main() {      int n,q;      scanf("%d%d",&n,&q);    for(int i=1;i<=n;i++)        scanf("%d",&A[i]);    build(1,n,1);      while(q--)     {          getchar();        char ch;        scanf("%c",&ch);        if(ch=='Q')        {            int x,y;            scanf("%d %d",&x,&y);            printf("%lld\n",query(x,y,1,n,1));        }        else         {            int x,y,z;            scanf("%d%d%d",&x,&y,&z);            update(x,y,z,1,n,1);         }    }      return 0;  }