Tag: math

Google ‘Proof without Words‘ you will find some interesting figures that are easy to understand. For example, the following figure is a vivid proof of the math formula Hint: …

The problem is from codeforces: http://www.codeforces.com/problemset/problem/230/B The input of the numbers exceed a 4-byte integer, therefore, a long type (int64) should be used in Java. I feel like I …

The problem is from codeforces: http://www.codeforces.com/problemset/problem/227/A The picture vividly illustrates the problem statement. Given 3 Points A, B and C, you are required to find out the direction. Read …

The problem is from codeforces: http://www.codeforces.com/problemset/problem/228/A The answer is to count the unique number of integers and substract from four. The SQL to the answer is: select 4 - …

Given two rectangles (as shown in the following figure), , are lower-left points while and are top-right points. We want to find out whether these two rectangles overlap each …