contents: make the Partition Equal Subset Sum link both (#246)
contents: make the Partition Equal Subset Sum link both (#246)

"Partition Equal Subset Sum" and "0/1 Knapsack"

Closes #234
yangshun/tech-interview-handbook,yangshun/tech-interview-handbook,yangshun/tech-interview-handbook,yangshun/tech-interview-handbook,yangshun/tech-interview-handbook