1422 - Candy!
Time Limit : 10 Second
Memory Limit : 128 MB
Submission: 469
Solved: 109
- Description
Halloween is coming! So xiaoY has to prepare M candies to treat the neighbor kids.
When this horrible night come, There are N little children ask xiaoY for candy, and each of them has different demand. For the i-th kid, his (or her) candy must not less than Min[i], and not greater than Max[i].
Now xiaoY wants to know how many ways he can give out all of his candies. (in case the large answer, please tell xiaoY the answer modular 10000007)
- Input
First line is an integer T, represents T cases followed:
N, M ---- Number of children, Number of candies.
(0<N<=20, 0<M<=10000)
Min[i], Max[i] ---- The lower bound and upper bound of I-th kid’s demand. (N lines)
(0<=Min[i] <= Max[i] <=M)
- Output
Output a number W which means total different ways of handing out the candies. (% 10000007)
- sample input
-
2 3 5 1 2 1 2 1 2 3 6 1 2 1 2 1 2
- sample output
-
Case #1: 3 Case #2: 1
- hint
For case 1, there are 3 ways to hand out:
1 + 2 + 2 = 5
2 + 1 + 2 = 5
2 + 2 + 1 = 5
For case 2, there is only one way to hand out:
2 + 2 + 2 = 6
- source