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:
1 #include <iostream>
2 #include <cstdio>
3 #include <cstring>
4 #include <fstream>
5 #include <ctime>
6 #include <cmath>
7 #include <cstdlib>
8 #include <algorithm>
9 #include <set>
10 #include <map>
11 #include <list>
12 #include <stack>
13 #include <queue>
14 #include <iterator>z
15 #include <vector>
16
17 using namespace std;
18
19 #define LL long long
20 #define INF 0x3f3f3f3f
21 #define MOD 1000000007
22 #define MAXN 10000010
23 #define MAXM 1000010
24
25
26 const int maxn = 200005;
27 int a[maxn];
28
29 int main()
30 {
31 string s;
32 while(cin>>s)
33 {
34 memset(a, 0, sizeof(a));
35 int i;
36 int len = s.size();
37 int c = 0;
38 for(i = 0; i < len; i++ )
39 a[c++] = s[i] - '0';
40 int b = 0;
41 for(i = 2*c-1; i >= c; i-- )
42 a[i] = a[b++];
43 for(i = 0; i < 2*c; i++ )
44 printf("%d", a[i]);
45 printf("
");
46 }
47
48 return 0;
49 }
1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <fstream> 5 #include <ctime> 6 #include <cmath> 7 #include <cstdlib> 8 #include <algorithm> 9 #include <set> 10 #include <map> 11 #include <list> 12 #include <stack> 13 #include <queue> 14 #include <iterator>z 15 #include <vector> 16 17 using namespace std; 18 19 #define LL long long 20 #define INF 0x3f3f3f3f 21 #define MOD 1000000007 22 #define MAXN 10000010 23 #define MAXM 1000010 24 25 26 int main() 27 { 28 string s; 29 cin >> s; 30 cout << s; 31 reverse(s.begin(), s.end()); //将字符串s中的顺序颠倒 32 cout << s << endl; 33 }