A palindrome partition is the partitioning of a string such that each separate substring is a palindrome.
For example, the string "ABACABA" could be partitioned in several different ways, such as {"A","B","A","C","A","B","A"}, {"A","BACAB","A"}, {"ABA","C","ABA"}, or {"ABACABA"}, among others.
You are given a string s. Return the minimum possible number of substrings in a palindrome partition of s.
Input
Input starts with an integer T (≤ 40), denoting the number of test cases.
Each case begins with a non-empty string s of uppercase letters with length no more than 1000.
Output
For each case of input you have to print the case number and the desired result.
Sample Input
3
AAAA
ABCDEFGH
QWERTYTREWQWERT
Output for Sample Input
Case 1: 1
Case 2: 8
Case 3: 5
题目大意就是说对于每一个一个字符串,都可以分解成若干个回文串。
现在让你求所给字符串分解成若干回文串的最小数量。
显然,分解成若干回文串的最大数量就是回文串的长度。
建立dp[i]
代表前i个字符分解成若干回文串的最小数量。
那么枚举前i
个字符中的j
,如果使得在字符串[j,i]
区间是回文串, 那么对于
dp[i] = min(dp[i], dp[j-1] + 1);
代码如下:
#include<bits/stdc++.h>
using namespace std;
bool judge(int x, int y, string &str)
{
while(x < y)
{
if(str[x] != str[y])
return false;
x ++, y --;
}
return true;
}
void solve(int cases)
{
string str;
cin >> str;
vector<int> dp(str.size()+1, str.size() + 1);
dp[0] = 0;
for(int i=1; i<str.size()+1; ++ i)
{
dp[i] = i;
for(int j=1; j<=i; ++ j)
{
if(judge(j-1, i-1, str))
dp[i] = min(dp[i], dp[j-1] + 1);
}
}
cout << "Case " << cases << ": " << dp[str.size()] << endl;
}
int main()
{
ios::sync_with_stdio(false);
int t;
cin >> t;
for(int i=1; i<=t; ++ i)
solve(i);
return 0;
}