POJ_3468_A Simple Problem with Integers_TLE

#include<iostream>    
#include<sstream>    
#include<string>    
#include<vector>    
#include<list>    
#include<set>    
#include<map>    
#include<stack>    
#include<queue>    
#include<algorithm>    
#include<cmath>    
#pragma warning(disable:4996)    
using std::cin;
using std::cout;
using std::endl;
using std::stringstream;
using std::string;
using std::vector;
using std::list;
using std::pair;
using std::set;
using std::multiset;
using std::map;
using std::multimap;
using std::stack;
using std::queue;
template<typename ElemType>
class Interval
{
public:
	ElemType first,second,sum,increment;
	Interval()
	{
		first = second =  sum = increment = 0;
	}
	Interval(const ElemType &f, const ElemType &s)
	{
		first = f;
		second = s;
		sum = increment = 0;
	}
	ElemType mid()
	{
		return first + (length() - 1) / 2;
	}
	ElemType length()
	{
		return second - first + 1;
	}
};
template<typename ElemType>
class SegTree
{
private:
	vector<Interval<ElemType> >tree;
public:
	SegTree() {}
	SegTree(const ElemType &n)
	{
		tree.resize(4 * n);
	}
	void resize(const ElemType &n)
	{
		tree.resize(n);
	}
	void pushUp(const ElemType &parent)//当前父区间之和为它的两个子区间之和
	{
		tree[parent].sum = tree[parent * 2].sum + tree[parent * 2 + 1].sum;
	}
	void pushDown(const ElemType &parent)//把父区间的延时标记下放给两个给两个子区间,然后父区间的延时标记清零
	{
		if (2 * parent < tree.size())
		{
			tree[2 * parent].increment += tree[parent].increment;
			tree[2 * parent].sum += tree[parent].increment*tree[2 * parent].length();
		}
		if (2 * parent + 1 < tree.size())
		{
			tree[2 * parent + 1].increment += tree[parent].increment;
			tree[2 * parent + 1].sum += tree[parent].increment*tree[2 * parent + 1].length();
		}
		tree[parent].increment = 0;
	}
	//以数组形式建立线段树,当数据离散化之后,调用build(min,max,1)
	void build(Interval<ElemType>interval, ElemType parent,ElemType &size)
	{
		tree[parent] = interval;
		if (interval.first == interval.second)
		{
			cin >> tree[parent].sum;
			size = std::max(size, parent);
			return;//当为元线段时停止递归
		}
		ElemType mid = (interval.first + interval.second) / 2;
		build({ interval.first,mid }, 2 * parent,size);
		build({ mid + 1,interval.second }, 2 * parent + 1,size);
		pushUp(parent);
	}
	//给闭区间内所有值加上增量increment,返回区间的下标值(如果区间被分割成多块,取下标最大),并且使父区间的sum+=length*increment
	void insert(Interval<ElemType>interval, ElemType parent, const ElemType &increment)
	{
		if (tree[parent].first == interval.first&&interval.second == tree[parent].second)
		{
			tree[parent].sum += increment*tree[parent].length();
			if (tree[parent].length() == 1)
			{
				tree[parent].increment = 0;
			}
			else
			{
				tree[parent].increment += increment;
			}
			return;
		}
		pushDown(parent);
		ElemType mid = tree[parent].mid();
		if (interval.second <= mid)
		{
			insert(interval, parent * 2, increment);
		}
		else if (interval.first > mid)
		{
			insert(interval, parent * 2 + 1, increment);
		}
		else
		{
			insert({ interval.first,mid }, parent * 2, increment);
			insert({ mid + 1,interval.second }, parent * 2 + 1, increment);
		}
		pushUp(parent);
	}
	//查询区间之和(假设要求的区间包含于最大区间)
	ElemType accumulate(pair<ElemType, ElemType>interval, ElemType parent)
	{
		//如果要查询的区间==当前区间
		if (tree[parent].first == interval.first&&interval.second == tree[parent].second)
		{
			//这时候应该从根据该区间的祖先区间的延时标记更新当前区间
			return tree[parent].sum;
		}
		pushDown(parent);
		ElemType mid = tree[parent].mid();
		if (interval.second <= mid)
		{
			return accumulate(interval, parent * 2);
		}
		else if (interval.first > mid)
		{
			return accumulate(interval, parent * 2 + 1);
		}
		return accumulate({ interval.first,mid }, parent * 2) + accumulate({ mid + 1,interval.second }, parent * 2 + 1);
	}
};
int main()
{
	//freopen("input.txt", "r", stdin);
	//freopen("output.txt","w",stdout); 
	int n, m;
	while (cin >> n >> m)
	{
		SegTree<long long> segtree(n);
		long long size=0;
		segtree.build({ 1,n }, 1,size);
		segtree.resize(size+1);
		cin.get();
		for (int i = 0; i < m; i++)
		{
			char order; cin >> order;
			if (order == 'Q')
			{
				long long left, right; cin >> left >> right;
				cout << segtree.accumulate({ left,right }, 1) << endl;
			}
			else
			{
				long long left, right, increment; cin >> left >> right >> increment;
				segtree.insert({ left,right }, 1, increment);
			}
		}
	}
	return 0;
}