SGU - 302 - BHTML 1.0 （栈的应用）

302. BHTML 1.0

Time limit per test: 0.25 second(s)
Memory limit: 65536 kilobytes

input: standard
output: standard

The hypertext markup language BHTML 1.0 has only two paired tags. They are UP /UP and DOWN /DOWN. The UP /UP tag capitalizes all letters inside its body (between an open tag and a close one), and DOWN /DOWN makes all inside the body letters lowercase. You are given the text consisting of latin letters and tags. Your task is to write the text right as it will be shown in the Bernet Explorer browser window. Tags in the text are arranged correctly, i.e. they form correct bracket sequence. If a letter lays inside several tags, its case is defined by the most inner tag.

Input

The input contains the string S with the text. The length of the string is a natural number not exceeding 1000. Tags are always written in uppercase.

Output

Write to the output text after the processing.

Example(s)

sample input	sample output
Thi<UP>sIs<DOWN>EaSY</DOWN>Pr<UP>O</UP>ble</UP>m	ThiSISeasyPROBLEm

思路：栈的应用，具体看代码;

AC代码：

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <stack>
using namespace std;

char str[1005];

int main() {
	while(gets(str) != NULL) {
		stack<int> s;
		int len = strlen(str);
		for(int i = 0; i < len; i++) {
			if(str[i] == '<') {
				if(str[i+1] == 'U') { s.push(1); i += 3; }
				else if(str[i+1] == 'D') { s.push(2); i += 5; }
				else if(str[i+1] == '/') {
					s.pop();
					if(str[i+2] == 'U') i += 4;
					else if(str[i+2] == 'D') i += 6;
				}
			}
			else if(s.empty()) {
				printf("%c", str[i]);
			}
			else if(s.top() == 1) {
				if(str[i] >= 'a' && str[i] <= 'z') printf("%c", str[i]-32);
				else printf("%c", str[i]);
			}
			else if(s.top() == 2) {
				if(str[i] >= 'A' && str[i] <= 'Z') printf("%c", str[i]+32);
				else printf("%c", str[i]);
			}
		}
		printf("\n");
	}
	return 0;
}

SGU - 302 - BHTML 1.0 （栈的应用）

原文：http://blog.csdn.net/u014355480/article/details/44275595