problem
1346. Check If N and Its Double Exist
solution1: two loop;
code
solution2:哈希表;
solution3: 使用set类型;
注意:
1. 倍数可能在后,也可能在前;
2. 熟练掌握map和set的使用方法;
参考
1. leetcode_1346. Check If N and Its Double Exist;
完