Palindrome Partitioning II
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| int dp[505][505];
int helper(string& s, int l, int r) {
if(l == r) return 0;
if(dp[l][r] != -1) return dp[l][r];
int& res = dp[l][r] = INT_MAX;
for(int i = l; i < r; i++) {
res = min(res, 1 + helper(s,l,i) + helper(s,i + 1, r));
}
return res;
}
void manacher(string s) {
string ss = "#";
for(auto& ch : s) {
ss.push_back(ch);
ss.push_back('#');
}
int l = 0, r = -1, n = ss.length();
vector<int> mana(n);
for(int i = 0; i < n; i++) {
mana[i] = max(0, min(r - i, (r + l - i >= 0 ? mana[r + l - i] : -1)));
while(i + mana[i] < n and i - mana[i] >= 0 and ss[i + mana[i]] == ss[i - mana[i]]) mana[i]++;
if(i + mana[i] > r) {
r = i + mana[i];
l = i - mana[i];
}
}
for(int i = 0; i < n; i++) {
int l = i - mana[i] + 1, r = i + mana[i] - 1;
while(l < r) {
if(ss[l] != '#' and ss[r] != '#') dp[l/2][r/2] = 0;
l++,r--;
}
}
}
int Solution::minCut(string A) {
memset(dp,-1,sizeof dp);
manacher(A);
return helper(A,0,A.length() - 1);
}
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