摘要：
Problem Description There are N points in total. Every point moves in certain direction and certain speed. We want to know at what time that the largest distance between any two points would be minimu... 阅读全文
摘要：
Problem Description Doctor Ghee is teaching Kia how to calculate the sum of two integers. But Kia is so careless and alway forget to carry a number when the sum of two digits exceeds 9. For example, w... 阅读全文