线段树 区间修改 总结

#include<fstream>
#include<string>
using namespace std;
ifstream fin("shuliec.in");
ofstream fout("shuliec.out");
class Node
{
public:
	long long l;
	long long r;
	long long Value;
	long long Lazy;
};
long long d[100001];
long long N;
long long ANS=0;
Node tree[400005];
void build(long long v,long long l,long long r)//v为结点标号
{
	tree[v].l=l;
	tree[v].r=r;
	if(l==r)
	{
		tree[v].Value=d[r];
		return ;
	}
	long long mid=(l+r)/2;
	build(v*2,l,mid);
	build(v*2+1,mid+1,r);
	tree[v].Value=tree[v*2].Value+tree[v*2+1].Value;
}
void update(long long v,long long l,long long r,long long m)
{
	tree[v].Value+=(r-l+1)*m;
	if(tree[v].l==l&&tree[v].r==r)
	{
		tree[v].Lazy+=m;
		return ;
	}
	if(tree[v].Lazy!=0)
	{
		tree[2*v].Lazy+=tree[v].Lazy;
		tree[2*v+1].Lazy+=tree[v].Lazy;
		tree[2*v].Value+=(tree[2*v].r-tree[2*v].l+1)*tree[v].Lazy;
		tree[2*v+1].Value+=(tree[2*v+1].r-tree[2*v+1].l+1)*tree[v].Lazy;
		tree[v].Lazy=0;
	}
	long long mid=(tree[v].l+tree[v].r)>>1;
	if(r<=mid)
		update(v*2,l,r,m);
	else
	{
		if(l>mid)
			update(2*v+1,l,r,m);
		else
		{
			update(2*v,l,mid,m);
			update(2*v+1,mid+1,r,m);
		}
	}
}
void query(long long v,long long l,long long r)
{
	if(tree[v].l==l&&tree[v].r==r)
	{
		ANS+=tree[v].Value;
		return ;
	}
	if(tree[v].Lazy!=0)
	{
		tree[2*v].Lazy+=tree[v].Lazy;
		tree[2*v+1].Lazy+=tree[v].Lazy;
		tree[2*v].Value+=(tree[2*v].r-tree[2*v].l+1)*tree[v].Lazy;
		tree[2*v+1].Value+=(tree[2*v+1].r-tree[2*v+1].l+1)*tree[v].Lazy;
		tree[v].Lazy=0;
	}
	long long mid=(tree[v].l+tree[v].r)/2;
	if(r<=mid)
		query(2*v,l,r);
	else
	{
		if(l>mid)
			query(2*v+1,l,r);
		else
		{
			query(2*v,l,mid);
			query(2*v+1,mid+1,r);
		}
	}
}
int main()
{
	int i,A,B,C;
	string temp;
	fin>>N;
	for(i=1;i<=N;i++)
		fin>>d[i];
	build(1,1,N);
	fin>>N;
	for(i=1;i<=N;i++)
	{
		fin>>temp;
		if(temp=="SUM")
		{
			fin>>A>>B;
			query(1,A,B);
			fout<<ANS<<endl;
			ANS=0;
		}
		if(temp=="ADD")
		{
			fin>>A>>B>>C;
			update(1,A,B,C);
		}
	}
	return 0;
}