7.Reverse Integer
The idea of solving problems: Using code that enforces type conversions, first using long, then judging values and then forcing them into int
1 Public classSolution {2 Public intReverseintx) {3 LongReverse_n =0;4 while(X! =0) {5Reverse_n = Reverse_n *Ten+ x%Ten;//Key Code6x = x/Ten;7 }8 if(Reverse_n > Integer.max_value | | Reverse_n <integer.min_value) {9 return 0;Ten } One return(int) Reverse_n; A } -}
9. Palindrome Number
1 Public classSolution {// problem Solving ideas: direct use of directly do reverse topics, if x = = Reverse_x is a palindrome number. 2 PublicBoolean Ispalindrome (intx) {3 if(X <0) {4 return false;5 }6 inty =x;7 Longreverse_x =0;8 while(X! =0) {9reverse_x = reverse_x *Ten+ x%Ten;Tenx = x/Ten; One } A //if (x > Integer.max_value | | x < integer.min_value) { - //return false; - // } the if(Y = = (int) {reverse_x) { - return true; - } - return false; + } -}
Leetcode topics in Java Design Practice class