LeetCode - Palindrome Partitioning II
Problem description
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.
Example:
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Input: "aab"
Output: 1
Explanation: The palindrome partitioning ["aa","b"] could be produced using 1 cut.
Analysis
First we can use a dp to find all palindromic substring. And we can use another dp to store the cur. dp[i] is the min cut for substring(0,i)
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public int minCut(String s) {
char[] c = s.toCharArray();
int n = c.length;
int[] cut = new int[n];
boolean[][] pal = new boolean[n][n];
for(int i = 0; i < n; i++) {
int min = i;
for(int j = 0; j <= i; j++) {
if(c[j] == c[i] && (j + 1 > i - 1 || pal[j + 1][i - 1])) {
pal[j][i] = true;
min = j == 0 ? 0 : Math.min(min, cut[j - 1] + 1);
}
}
cut[i] = min;
}
return cut[n - 1];
}
What to improve
- when we do cut for palindromic substring, we can use a cut array as a dp and don’t use the general dfs method.