题目：
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.
输入描述:
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.
输出描述:
You need to answer all Q commands in order. One answer in a line.
示例1
输入
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
输出
4
55
9
15
思路：和上篇差不多，一个经典树状数组稍微变形
#include<bits/stdc++.h> using namespace std; long long n,q; int a[101010]; long long lowbit(long long x) { return x&-x; } void add(long long i,long long x) { while(i<=n) { a[i]+=x; i+=lowbit(i); } } long long sum(long long i) { long long ans=0; while(i>0) { ans+=a[i]; i-=lowbit(i); } return ans; } int main() { cin>>n>>q; long long x,a,b,c; for(int i=1;i<=n;i++) { cin>>x; add(i,x); } string s; while(q--) { cin>>s; if(s=="Q"){ cin>>a>>b; cout<<sum(b)-sum(a-1)<<endl; } else{ cin>>a>>b>>c; for(int i=a;i<=b;i++) add(i,c); } } return 0; }
