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.
这道题很惭愧,想直接在上一道题的代码上改,结果还是重写了。
之前为了方便算回文,插入“#”。但是程序会报内存不足,所以不能用这种扩展方式,只能拿string.size来建dp数组
后面根据数组,用dp继续做cut。cut的时候 cut j = min(cut j , cut i +1 (if dp[i+1][j] == 1)).要注意该推导式不需要dp[0][i] == 1
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class
Solution { public : int
minCut(string s) { vector<vector < int > >dp; int
len = s.size(); if (len == 1) return
0; for ( int
i = 0 ; i < len ;i++) { vector< int > tp(len,0); dp.push_back(tp); } for ( int
i = 0 ; i < len ; i++) dp[i][i] = 1; for ( int
i = 0 ; i < len ;i++) { int
j = 1; while (i-j>=0 && i+j<len && s[i-j] == s[i+j]) { dp[i-j][i+j] = 1; j++; } int
x = i , y =i+1; while (x>=0 && y<len) { if (s[x]==s[y]) { dp[x][y]=1; x--; y++; } else break ; } } int
num = 0; if (dp[0][len-1]==1) return
0; vector< int > cut(len ,1); for ( int
i = 0 ; i < len ;i++) if (dp[0][i]==1)cut[i] = 1; else cut[i] = i+1; for ( int
i = 1;i<len;i++) { for ( int
j = 0 ;j <i ;j++) { if (j+1<len && dp[j+1][i]==1) { cut[i] = min(cut[j]+1,cut[i]); } } } return
cut[len-1]-1; } }; |
Palindrome Partitioning II,布布扣,bubuko.com
原文:http://www.cnblogs.com/pengyu2003/p/3669533.html