杭电oj1318（Palindromes）

杭电oj1318（Palindromes）

题目描述

输入一串字符，判断是否为回文数或者镜像字符串

Sample Input

NOTAPALINDROME
ISAPALINILAPASI
2A3MEAS
ATOYOTA

Sample Output

NOTAPALINDROME – is not a palindrome.

ISAPALINILAPASI – is a regular palindrome.

2A3MEAS – is a mirrored string.

ATOYOTA – is a mirrored palindrome.

答案

简单题~
题目明确说了不会输入非法字符，而且0是非法的
剩下的就是判断回文和镜像了

#include <string.h>
#include <ctype.h>
#include <iostream>

using namespace std;

void converse(char *);
bool is_palindrome(char *);
bool is_mirror(char *);

int main() {
	
	char str[50];
	bool palindrome, mirror;
	while (cin >> str) {

		/*Judge*/
		palindrome = is_palindrome(str);
		mirror = is_mirror(str);

		/*Output*/
		if (palindrome && mirror)
			printf("%s -- is a mirrored palindrome.\n", str);
		else if (palindrome)
			printf("%s -- is a regular palindrome.\n", str);
		else if (mirror)
			printf("%s -- is a mirrored string.\n", str);
		else
			printf("%s -- is not a palindrome.\n", str);
		printf("\n");
	}
}

void converse(char *str) {
	char *p = str, *q, tmp;
	for (q = str; *q != '\0'; q++)
		;
	q--;
	for (; p < q; p++, q--)
		tmp = *p, *p = *q, *q = tmp;
}

bool is_palindrome(char *str) {
	int len = strlen(str);
	char *reverse = new char[len + 1];
	strcpy_s(reverse, len + 1, str);
	converse(reverse);
	return !strcmp(str, reverse);
}

char reverse_char(char ch) {
	switch (ch) {
	case 'A':case 'H':case 'I':case 'M':
	case 'O':case 'T':case 'U':case 'V':
	case 'W':case 'X':case 'Y':case '1':case '8':
		return ch;
	case 'E':
		return '3';
	case 'J':
		return 'L';
	case 'L':
		return 'J';
	case 'S':
		return '2';
	case 'Z':
		return '5';
	case '2':
		return 'S';
	case '3':
		return 'E';
	case '5':
		return 'Z';
	default:
		return '\0';
	}
}

bool is_mirror(char *str) {
	int i, j;

	for (i = 0, j = strlen(str) - 1; i <= j; i++, j--) //注意是 i <= j
		if (str[i] != reverse_char(str[j])) {
			return false;
		}
	return true;
}