My algorithm is
1. sort wait time min -> max
2. variable time declared to add total time
3. add minimal wait time and exam time to var(time)
4. add exam time everybody
5. if time > freetime print time-freetime
   else print 0
I think my algorithm is right ,but I got WA #7
Could you help me plz?

I see.
My algorithm has a little mistake.
Now I got AC.

you're wrong !
Let consider this test :
2
100 50 160
200 250 300
your answer : 100
correct answer : 150

Try test
2
50 10 50
150 20 200
Answer: 10

Phan Hoài Nam - Đại học Ngoại ngữ Tin Học TP.HCM -  Your test case is wrong. T2 cant be greater than 240

Edited by author 25.09.2014 20:32

Edited by author 25.09.2014 20:33