CodeForces 688B-Lovely Palindromes

题意:
　　给出一串数字,要你输出它的回文数，就这么简单.

分析:
　　可以用数组去做，也可以用reversed()函数(这个更简单).

 

 

代码如下:

 

 

#include <iostream>
#include <cstdio>
#include <cstring>
#include <fstream>
#include <ctime>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <set>
#include <map>
#include <list>
#include <stack>
#include <queue>
#include <iterator>z
#include <vector>

using namespace std;

#define LL long long
#define INF 0x3f3f3f3f
#define MOD 1000000007
#define MAXN 10000010
#define MAXM 1000010


const int maxn = 200005;
int a[maxn];

int main()
{
    string s;
    while(cin>>s)
    {
        memset(a, 0, sizeof(a));
        int i;
        int len = s.size();
        int c = 0;
        for(i = 0; i < len; i++ )
            a[c++] = s[i] - '0';
        int b = 0;
        for(i = 2*c-1; i >= c; i-- )
            a[i] = a[b++];
        for(i = 0; i < 2*c; i++ )
            printf("%d", a[i]);
        printf("\n");
    }

    return 0;
}

 

 

 

#include <iostream>
#include <cstdio>
#include <cstring>
#include <fstream>
#include <ctime>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <set>
#include <map>
#include <list>
#include <stack>
#include <queue>
#include <iterator>z
#include <vector>

using namespace std;

#define LL long long
#define INF 0x3f3f3f3f
#define MOD 1000000007
#define MAXN 10000010
#define MAXM 1000010


int main()
{
    string s;
    cin >> s;
    cout << s;
    reverse(s.begin(), s.end());    //将字符串s中的顺序颠倒
    cout << s << endl;
}