7.reverse

Given a 32-bit signed integer, reverse digits of an integer.

Example 1:

Example 2:

Example 3:

Note:

Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231,  231 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

关键点：

1.题目给出输入的数小于INT_MAX，但反转过后不一定小于INT_MAX，所以要进行判断。

#include<iostream>

#include<climits>

using namespace std;

intinverse(intx){

    intc,y,newnum=0,oldnum=x;

    c=oldnum/10;

    y=oldnum%10;

    while(oldnum!=0)

    {

        if(newnum>INT_MAX/10|| newnum

        {

            return0;

        }

        newnum=newnum*10+y;

        oldnum=c;

        c=oldnum/10;

        y=oldnum%10;

    }

    returnnewnum;

}

intmain(intargc,constchar* argv[]) {

    // insert code here...

    inta,b;

    while(cin>>a){

        b=inverse(a);

        cout<

    }

    cout << "Hello, World!\n";

    return 0;

}