摘要：
Balanced numbers have been used by mathematicians for centuries. A positive integer is considered a balanced number if: 1) Every even digit appears an 阅读全文
摘要：
soda has an integer array a1,a2,…,ana1,a2,…,an. Let S(i,j)S(i,j) be the sum of ai,ai+1,…,ajai,ai+1,…,aj. Now soda wants to know the value below: ∑i=1n 阅读全文