OJ-Problems-Source/.ACM-Templates/.Not classified/Manacher/main.cpp
2016-08-13 23:36:53 +08:00

14 lines
478 B
C++

inline int Manacher(int a[], int n, int ret[]) {
int MaxR = -1, where = 0, Ans = 0;
for (int i = 1; i <= n; i++) {
int &it = ret[i]; it = 0;
if (i <= MaxR) it = min(ret[where * 2 - i], MaxR - i);
while (i - it - 1 >= 1 && i + it + 1 <= n && a[i - it - 1] == a[i + it + 1]) it++;
if (it + i > MaxR) MaxR = it + i, where = i;
int tmp = (it << 1) + 1; tmp >>= 1;
if (a[i - it] != '$') tmp++; //如果a[i - it]不是分割符
Ans = max(Ans, tmp);
}
return Ans;
}