LeetCode7 Reverse Integer

Test instructions

Reverse digits of an integer.

EXAMPLE1:X = 123, return 321
example2:x = -123, return-321

Analysis:

The idea is very simple, pay attention to special cases such as 10,100 and int overflow situation can be;

Start with an array to save you first, and then multiply the corresponding coefficients to make the result, but the code is lengthy and cost space;

A while loop can be used directly;

Code Listing 1:

1 classSolution {2  Public:3     intReverseintx) {4         Long Longresult =0;5          while(X! =0) {6             inttemp = x%Ten;7X/=Ten;8result = result *Ten+temp;9             if(Result >0x7FFFFFFF|| Result <-0x7FFFFFFF) {Ten                 return 0; One             } A         } -         returnresult; -     } the};

Viewing the discussion area, it is found that there is a kind of realization method without 0x7fffffff judgment, as reference;

Code Listing 2:

1 classSolution {2  Public:3     intReverseintx) {4         intresult =0;5          while(X! =0) {6             inttemp = x%Ten;7X/=Ten;8             intNewresult = result *Ten+temp;9             if((newresult-temp)/Ten!=result) {Ten                 return 0; One             } Aresult =Newresult; -         } -         returnresult; the     } -};

LeetCode7 Reverse Integer