Reverse Integer

Reverse digits of an integer.

Example1: x = 123, return 321 Example2: x = -123, return -321

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Note: The input is assumed to be a 32-bit signed integer. Your function should return 0 when the reversed integer overflows.

class Solution { public: int reverse(int x) { int tmp=0; int flag=1; if(x<0) { flag=-1; x=0-x; } for(;x>0;) { int t=tmp; tmp=tmp*10+x%10; //判断是否溢出 if((tmp-x%10)/10 != t) { return 0; } x/=10; } return tmp*flag; } };