Let's Chat

Let’s Chat
Time Limit: 1 Second Memory Limit: 65536 KB

ACM (ACMers’ Chatting Messenger) is a famous instant messaging software developed by Marjar Technology Company. To attract more users, Edward, the boss of Marjar Company, has recently added a new feature to the software. The new feature can be described as follows:

If two users, A and B, have been sending messages to each other on the last m consecutive days, the “friendship point” between them will be increased by 1 point.

More formally, if user A sent messages to user B on each day between the (i - m + 1)-th day and the i-th day (both inclusive), and user B also sent messages to user A on each day between the (i - m + 1)-th day and the i-th day (also both inclusive), the “friendship point” between A and B will be increased by 1 at the end of the i-th day.

Given the chatting logs of two users A and B during n consecutive days, what’s the number of the friendship points between them at the end of the n-th day (given that the initial friendship point between them is 0)?
Input

There are multiple test cases. The first line of input contains an integer T (1 ≤ T ≤ 10), indicating the number of test cases. For each test case:

The first line contains 4 integers n (1 ≤ n ≤ 109), m (1 ≤ m ≤ n), x and y (1 ≤ x, y ≤ 100). The meanings of n and m are described above, while x indicates the number of chatting logs about the messages sent by A to B, and y indicates the number of chatting logs about the messages sent by B to A.

For the following x lines, the i-th line contains 2 integers la, i and ra, i (1 ≤ la, i ≤ ra, i ≤ n), indicating that A sent messages to B on each day between the la, i-th day and the ra, i-th day (both inclusive).

For the following y lines, the i-th line contains 2 integers lb, i and rb, i (1 ≤ lb, i ≤ rb, i ≤ n), indicating that B sent messages to A on each day between the lb, i-th day and the rb, i-th day (both inclusive).

It is guaranteed that for all 1 ≤ i < x, ra, i + 1 < la, i + 1 and for all 1 ≤ i < y, rb, i + 1 < lb, i + 1.
Output

For each test case, output one line containing one integer, indicating the number of friendship points between A and B at the end of the n-th day.
Sample Input

2
10 3 3 2
1 3
5 8
10 10
1 8
10 10
5 3 1 1
1 2
4 5

Sample Output

3
0

Hint

For the first test case, user A and user B send messages to each other on the 1st, 2nd, 3rd, 5th, 6th, 7th, 8th and 10th day. As m = 3, the friendship points between them will be increased by 1 at the end of the 3rd, 7th and 8th day. So the answer is 3.

#include <iostream>#include <cstdio>#include <cmath>#include <algorithm>using namespace std;struct tx{    int l, r;} A[250], B[250];int main(){    int n, m, x, y, t, i, j, L, R, s, sum;    cin>>t;    while(t--)    {        sum = 0;        cin>>n>>m>>x>>y;        for(i = 0; i < x;i++)        {            cin>>A[i].l>>A[i].r;        }        for(i = 0; i < y; i++)        {            cin>>B[i].l>>B[i].r;        }        i = 0;        j = 0;        while(i < x && j < y)        {            if(A[i].l > B[j].r)                j++;            if(B[j].l > A[i].r)                i++;            else            {                L = max(A[i].l,B[j].l);                R = min(A[i].r,B[j].r);                if(A[i].r < B[j].r)                    i++;                else                    j++;                s = R - L + 1;                if(s >= m)                    sum = sum + s - m + 1;            }        }        cout<<sum<<endl;    }    return 0;}