标签：thunder pos blog sizeof div sed 问题 sam win
| Time Limit: 1000MS | Memory Limit: 65536K | |
| Total Submissions: 3951 | Accepted: 2078 |
Description
We give the following inductive definition of a “regular brackets” sequence:
For instance, all of the following character sequences are regular brackets sequences:
(), [], (()), ()[], ()[()]
while the following character sequences are not:
(, ], )(, ([)], ([(]
Given a brackets sequence of characters a1a2 … an, your goal is to find the length of the longest regular brackets sequence that is a subsequence of s. That is, you wish to find the largest m such that for indices i1, i2, …, im where 1 ≤ i1 < i2 < … < im ≤ n, ai1ai2 … aim is a regular brackets sequence.
Given the initial sequence ([([]])], the longest regular brackets subsequence is
[([])].
Input
The input test file will contain multiple test cases. Each input test case consists of a single line containing only the characters
(, ), [, and ]; each input test will have length between 1 and 100, inclusive. The end-of-file is marked by a line containing the word “end” and should not be processed.
Output
For each input case, the program should print the length of the longest possible regular brackets subsequence on a single line.
Sample Input
((()))
()()()
([]])
)[)(
([][][)
end
Sample Output
6
6
4
0
6
Source
id=2955
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int const INF = 0x3fffffff;
char s[205];
int dp[205][205];
int main()
{
while(scanf("%s", s) != EOF && strcmp(s, "end") != 0)
{
int len = strlen(s);
memset(dp, 0, sizeof(dp));
for(int i = 0; i < len; i++)
dp[i][i] = 1;
for(int l = 1; l < len; l++)
{
for(int i = 0; i < len - l; i++)
{
int j = i + l;
dp[i][j] = INF;
if((s[i] == '(' && s[j] == ')') || (s[i] == '[' && s[j] == ']'))
dp[i][j] = dp[i + 1][j - 1];
for(int k = i; k < j; k++)
dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j]);
}
}
printf("%d\n", len - dp[0][len - 1]);
}
}
标签：thunder pos blog sizeof div sed 问题 sam win
原文地址：http://www.cnblogs.com/jzssuanfa/p/7040016.html
