题目:
Given a string s, partition s such that every substring of the partition is a palindrome.
Return the minimum cuts needed for a palindrome partitioning of s.
For example, given s = "aab"
,
Return 1
since the palindrome partitioning ["aa","b"]
could
be produced using 1 cut.
解题:
思路类似Palindrome Partitioning,首先构造DP数组,然后再次dp,状态转移方程:
f[j] = min(f[j], f[i - 1] + 1);
f[i + 1] = min(f[i + 1], f[i] + 1);
代码:
class Solution { public: int minCut(string s) { makeDP(s); int f[SIZE]; if(s == "") return 0; for(int i = 0; i <= s.size(); i ++) f[i] = INF; f[0] = 1; for(int i = 0; i < s.size(); i ++) { for(int j = i + 1; j < s.size(); j ++) if(dp[i][j]) { if(i) f[j] = min(f[j], f[i - 1] + 1); else f[j] = 1; } f[i + 1] = min(f[i + 1], f[i] + 1); } return f[s.size() - 1] - 1; } private: static const int SIZE = 2000; static const int INF = 1 << 30; bool dp[SIZE][SIZE]; void makeDP(string s) { memset(dp, 0, sizeof(dp)); for(int i = s.size() - 1; i >= 0; i --) for(int j = i; j < s.size(); j ++) if(s[i] == s[j] && (i == j || j == i + 1 || dp[i + 1][j - 1])) dp[i][j] = 1; } };