Codeforces 816B Karen and Coffee（前缀和）

B. Karen and Coffee

time limit per test

2.5 seconds

memory limit per test

512 megabytes

input

standard input

output

standard output

To stay woke and attentive during classes, Karen needs some coffee!

Karen, a coffee aficionado, wants to know the optimal temperature for brewing the perfect cup of coffee. Indeed, she has spent some time reading several recipe books, including the universally acclaimed "The Art of the Covfefe".

She knows n coffee recipes. The i-th recipe suggests that coffee should be brewed between li and ri degrees, inclusive, to achieve the optimal taste.

Karen thinks that a temperature is admissible if at least k recipes recommend it.

Karen has a rather fickle mind, and so she asks q questions. In each question, given that she only wants to prepare coffee with a temperature between a and b, inclusive, can you tell her how many admissible integer temperatures fall within the range?

Input

The first line of input contains three integers, n, k (1 ≤ k ≤ n ≤ 200000), and q (1 ≤ q ≤ 200000), the number of recipes, the minimum number of recipes a certain temperature must be recommended by to be admissible, and the number of questions Karen has, respectively.

The next n lines describe the recipes. Specifically, the i-th line among these contains two integers li and ri (1 ≤ li ≤ ri ≤ 200000), describing that the i-th recipe suggests that the coffee be brewed between li and ri degrees, inclusive.

The next q lines describe the questions. Each of these lines contains a and b, (1 ≤ a ≤ b ≤ 200000), describing that she wants to know the number of admissible integer temperatures between a and b degrees, inclusive.

Output

For each question, output a single integer on a line by itself, the number of admissible integer temperatures between a and b degrees, inclusive.

Examples

input

3 2 491 9492 9797 9992 9493 9795 9690 100

output

3304

input

2 1 11 1200000 20000090 100

output

0

Note

In the first test case, Karen knows 3 recipes.

1. The first one recommends brewing the coffee between 91 and 94 degrees, inclusive. 
2. The second one recommends brewing the coffee between 92 and 97 degrees, inclusive. 
3. The third one recommends brewing the coffee between 97 and 99 degrees, inclusive. 

A temperature is admissible if at least 2 recipes recommend it.

She asks 4 questions.

In her first question, she wants to know the number of admissible integer temperatures between 92 and 94 degrees, inclusive. There are 3: 92, 93 and 94 degrees are all admissible.

In her second question, she wants to know the number of admissible integer temperatures between 93 and 97 degrees, inclusive. There are 3: 93, 94 and 97 degrees are all admissible.

In her third question, she wants to know the number of admissible integer temperatures between 95 and 96 degrees, inclusive. There are none.

In her final question, she wants to know the number of admissible integer temperatures between 90 and 100 degrees, inclusive. There are 4: 92, 93, 94 and 97 degrees are all admissible.

In the second test case, Karen knows 2 recipes.

1. The first one, "wikiHow to make Cold Brew Coffee", recommends brewing the coffee at exactly 1 degree. 
2. The second one, "What good is coffee that isn't brewed at at least 36.3306 times the temperature of the surface of the sun?", recommends brewing the coffee at exactly 200000 degrees. 

A temperature is admissible if at least 1 recipe recommends it.

In her first and only question, she wants to know the number of admissible integer temperatures that are actually reasonable. There are none.

题目大意：

    有N个区间，Q个询问，每次输入一个区间。问在这个询问的区间中，有多少个整数在那N个区间中至少出现了K次。

解题思路：

    前缀和的经典运用。要想使某个区间同时加上一个数，不需要把每个都加，只需要像lazy tag一样在起点加上这个数，终点的下一个减去这个数。最后求一遍前缀和就一次性的把前面的全部区间都更新了。

    所以这题，先利用上面的方法得到每个点的出现次数，再用一个前缀和就可以O（1）的得到某一个区间满足条件的点的数目。

AC代码：

#include <iostream>#include <algorithm>#include <cstdio>#include <cstring>#include <cmath>#include <cstdlib>#include <ctime>#include <vector>#include <queue>#include <stack>#include <string>#include <map>using namespace std;#define LL long long#define INF 0x3f3f3f3f#define fi first#define se second#define mem(a,b) memset((a),(b),sizeof(a))const int MAXN=200000+3;int cnt[MAXN],sum[MAXN];int N,K,Q;int main(){    scanf("%d%d%d",&N,&K,&Q);    for(int i=0;i<N;++i)    {        int l,r;        scanf("%d%d",&l,&r);        ++cnt[l];        --cnt[r+1];    }    for(int i=1;i<MAXN;++i)    {        cnt[i]+=cnt[i-1];        if(cnt[i]>=K)            ++sum[i];    }    for(int i=1;i<MAXN;++i)        sum[i]+=sum[i-1];    for(int i=0;i<Q;++i)    {        int l,r;        scanf("%d%d",&l,&r);        printf("%d\n",sum[r]-sum[l-1]);    }        return 0;}