@[xun0](/space/show?uid=73733) 使用scanf
by Lstdo @ 2018-08-18 13:10:58
@[luositing](/space/show?uid=53930) 谢谢大佬，虽然不太懂原理
by xun0 @ 2018-08-18 22:24:40
#include <iostream>
using namespace std;
int n,m,f[2000010];
int lowbit(int i)
{
return i&-i;
}
void he(int x,int i)
{
while(x<=n)
{
f[x]+=i;
x+=lowbit(x);
}
}
int sum(int x)
{
int ans=0;
while(x!=0)
{
ans+=f[x];
x-=lowbit(x);
}
return ans;
}
int main()
{
cin>>n>>m;
for(int i=1;i<=n;i++)
{
int a;
cin>>a;
he(i,a);
}
for(int i=1;i<=m;i++)
{
int a,b,c;
cin>>a>>b>>c;
if(a==1)
he(b,c);
if(a==2)
cout<<sum(c)-sum(b-1)<<endl;
}
}
by outofstrait @ 2018-09-16 11:31:38
其实cin也可以
by outofstrait @ 2018-09-16 11:32:12
你看看
by outofstrait @ 2018-09-16 11:32:31