标签：
题意 在一个字符串中插入一个字母使其变成一个回文串 可以的话输出这个回文串 否则NA
大水题 插入情况最多就26*11种 可以直接暴力
#include
#include
using namespace std;
const int N = 20;
char s[N], p[N];
int l;
bool ispal()
{
for(int i = 0; i < (l + 1) / 2; ++i)
if(p[i] != p[l - i]) return false;
return true;
}
int main()
{
int i, j, k;
scanf("%s", s);
l = strlen(s);
for(char c = ‘a‘; c <= ‘z‘; ++c)
{
for(k = 0; k <= l; ++k)
{
i = j = -1;
while(i < k - 1) p[++j] = s[++i];
p[++j] = c;
while(i < l - 1) p[++j] = s[++i];
if(ispal())
{
printf("%s\n", p);
return 0;
}
}
}
printf("NA\n");
return 0;
}
复制代码
A. Mr. Kitayuta‘s Gift Mr. Kitayuta has kindly given you a string s consisting of lowercase English letters. You are asked to insert exactly one lowercase English letter into s to make it a palindrome. A palindrome is a string that reads the same forward and backward. For example, "noon", "testset" and "a" are all palindromes, while "test" and "kitayuta" are not.
You can choose any lowercase English letter, and insert it to any position of s, possibly to the beginning or the end of s. You have to insert a letter even if the given string is already a palindrome.
If it is possible to insert one lowercase English letter into s so that the resulting string will be a palindrome, print the string after the insertion. Otherwise, print "NA" (without quotes, case-sensitive). In case there is more than one palindrome that can be obtained, you are allowed to print any of them.
Input
The only line of the input contains a string s (1?≤?|s|?≤?10). Each character in s is a lowercase English letter.
Output
If it is possible to turn s into a palindrome by inserting one lowercase English letter, print the resulting string in a single line. Otherwise, print "NA" (without quotes, case-sensitive). In case there is more than one solution, any of them will be accepted.
Sample test(s) input
revive
[/code]
output
reviver
[/code]
input
ee
[/code]
output
eye[/code]
input
kitayuta
[/code]
output
NA[/code]
文章由http://yy.china.com.cn/shnk/xb/整篇转载
标签：
原文地址：http://www.cnblogs.com/ldico/p/4234628.html
