线段树的TLE代码（pku 3468）

songzhipeng08 2010-08-25 12:03:43

试题链接：
http://124.205.79.250/JudgeOnline/problem?id=3468
问题：
下面的代码是我花了一上午的时间打出来的（好吧，欢迎鄙视本菜^_^），不明白为什么会超时，我觉得我的add和query函数都是O(logN)的复杂度呀（估计不是，否则不会超时了……），请各位大牛看看为什么会超时（帮忙分析一下时间复杂度），谢谢。
代码：



#include <iostream>

#include <fstream>

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <string>

#include <cmath>

#include <cctype>

#include <set>

#include <map>

#include <bitset>

#include <stack>

#include <queue>

#include <algorithm>

#include <functional>



using namespace std;

#define M 100005

struct A

{

	int lt, rt;

	long long sum;

}tree[M * 5];

int len;

void maketree(int = 1, int = len, int = 1);

void insert(int , int , int = 1);

long long query(int, int, int = 1);

void add(int, int, long long, int = 1);

void swap(int &, int &);

void print();

int main()

{

	int qs, t;

	// memset(tree, 0, sizeof tree);

	scanf("%d %d", &len, &qs);

	maketree();

	//print();

	for (int i = 1; i <= len; ++ i)

	{

		scanf("%d", &t);

		insert(t, i);

	}

	//print();

	char str[2];

	int a, b;

	long long c;

	for (int i = 0; i < qs; ++ i)

	{

		scanf("%s", str);

		if (str[0] == 'Q')

		{

			scanf("%d%d", &a, &b);

			if (a > b) swap(a, b);

			printf("%lld\n", query(a, b));

		}

		else

		{

			scanf("%d%d%lld", &a, &b, &c);

			if (a > b) swap(a, b);

			add(a, b, c);

			//print();

		}

	}

	//system("pause");

	return 0;

}

// 调试用 

void print()

{

	printf("----打印开始----\n");

	printf("下标\t左端点\t右端点\t和值\n");

	for (int i = 0; i < 30; ++ i)

	{

		printf("%d\t%d\t%d\t%d\n", i, tree[i].lt, tree[i].rt, tree[i].sum);

	} 

	printf("----打印结束----\n");

}

void maketree(int lt, int rt, int pos)

{

	tree[pos].sum = 0;

	tree[pos].lt = lt;

	tree[pos].rt = rt;

	if (lt == rt) return;

	int mid = (lt + rt) / 2;

	maketree(lt, mid, pos << 1);

	maketree(mid + 1, rt, (pos << 1) + 1);

}

void insert(int value, int id, int pos)

{

	tree[pos].sum += value;

	if (tree[pos].lt == tree[pos].rt) return;

	int mid = (tree[pos].lt + tree[pos].rt) / 2;

	if (id <= mid)

		insert(value, id, pos << 1);

	else

		insert(value, id, (pos << 1) + 1);

}

long long query(int lt, int rt, int pos)

{

	if (lt == tree[pos].lt && rt == tree[pos].rt)

		return tree[pos].sum;

	int mid = (tree[pos].lt + tree[pos].rt) / 2;

	if (rt <= mid)

		return query(lt, rt, pos << 1);

	else if (lt > mid)

		return query(lt, rt, (pos << 1) + 1);

	else

		return query(lt, mid, pos << 1) + query(mid + 1, rt, (pos << 1) + 1);

}

void add(int lt, int rt, long long value, int pos)

{

	tree[pos].sum += value * (rt - lt + 1);

	if (tree[pos].lt == tree[pos].rt)

		return;

	int mid = (tree[pos].lt + tree[pos].rt) / 2;

	if (rt <= mid)

		add(lt, rt, value, pos << 1);

	else if (lt > mid)

		add(lt, rt, value, (pos << 1) + 1);

	else

	{

		add(lt, mid, value, pos << 1);

		add(mid + 1, rt, value, (pos << 1) + 1);

	}

}

void swap(int & a, int & b)

{

	int t = a;

	a = b;

	b = t;

}