func_code_string: #include <bits/stdc++.h>   using namespace std;   long long rdtsc() {     long long tmp;     asm( rdtsc  :  =A (tmp));     return tmp;   }   inline int myrand() { return abs((rand() << 15) ^ rand()); }   inline int rnd(int x) { return myrand() % x; }   const int maxn = (int)1e5;   char s[maxn + 1];   long long hs[maxn + 1];   const long long Q = 239017;   long long qs[maxn + 1];   const int maxc = 26;   int colors[maxc][maxn + 1];   void precalc(int n) {     hs[0] = 0;     for (int i = 0; i < n; ++i) {       hs[i + 1] = hs[i];       hs[i + 1] *= Q;       hs[i + 1] += (int)s[i];     }     qs[0] = 1;     for (int i = 1; i <= n; ++i) qs[i] = qs[i - 1], qs[i] *= Q;     for (int color = 0; color < maxc; ++color) {       colors[color][0] = 0;       for (int i = 0; i < n; ++i)         colors[color][i + 1] = colors[color][i] + (s[i] == color +  a );     }   }   inline long long getHash(int pos, int len) {     long long tmp = hs[pos];     tmp *= qs[len];     long long res = hs[pos + len];     res -= tmp;     return res;   }   const int maxl = 17;   inline int commonLen(int left, int right, int n) {     assert(left < right);     int ans = 0;     for (int it = maxl - 1; it >= 0; --it) {       if (right + ans + (1 << it) <= n &&           getHash(left, ans + (1 << it)) == getHash(right, ans + (1 << it)))         ans += (1 << it);     }     return ans;   }   int gray[maxl][maxn];   int grayLen[maxl];   long long wholeTaken[maxn + 1];   long long getInitial(int n) {     for (int i = 0; i <= n; ++i) wholeTaken[i] = 0;     long long res = 0;     for (int len = 0; len < maxl; ++len) {       grayLen[len] = (1 << (len + 1)) - 1;       int n0 = n - grayLen[len] + 1;       for (int i = 0; i < n0; ++i) {         int &current = gray[len][i];         current = 0;         if (!len) {           current = 1;           continue;         }         int half = i + grayLen[len - 1];         int *countMidColor = colors[s[half] -  a ];         if (gray[len - 1][i] &&             countMidColor[i + grayLen[len]] - countMidColor[i] == 1 &&             getHash(i, grayLen[len - 1]) == getHash(half + 1, grayLen[len - 1]))           current = 1;       }       long long sqrLen = (long long)grayLen[len] * grayLen[len];       for (int i = 0; i < n0; ++i) {         if (!gray[len][i]) continue;         wholeTaken[i] += sqrLen;         wholeTaken[i + grayLen[len]] -= sqrLen;         res += sqrLen;       }     }     for (int i = 1; i <= n; ++i) wholeTaken[i] += wholeTaken[i - 1];     return res;   }   long long changes[maxc][maxn];   void findChanges(int n) {     for (int i = 0; i < maxc; ++i)       for (int j = 0; j < n; ++j) changes[i][j] = 0;     for (int len = 0; len < maxl; ++len) {       int n0 = n - grayLen[len] + 1;       for (int i = 0; i < n0; ++i) {         if (!len) {           for (int c = 0; c < maxc; ++c)             if (c +  a  != s[i]) changes[c][i] += 1;           continue;         }         int half = i + grayLen[len - 1];         if (!gray[len - 1][i] && !gray[len - 1][half + 1]) continue;         long long sqrLen = (long long)grayLen[len] * grayLen[len];         if (gray[len - 1][i] &&             getHash(i, grayLen[len - 1]) == getHash(half + 1, grayLen[len - 1])) {           for (int c = 0; c < maxc; ++c) {             int *countMidColor = colors[c];             if (countMidColor[i + grayLen[len]] - countMidColor[i] == 0) {               changes[c][half] += sqrLen;             }           }         }         int *countMidColor = colors[s[half] -  a ];         int firstLen = commonLen(i, half + 1, n);         if (firstLen >= grayLen[len - 1]) continue;         int left = i + firstLen, right = left + grayLen[len - 1] + 1;         int secondLen = commonLen(left + 1, right + 1, n);         if (firstLen + 1 + secondLen < grayLen[len - 1]) continue;         if (gray[len - 1][half + 1] &&             countMidColor[half + 1 + grayLen[len - 1]] -                     countMidColor[half + 1] ==                 0)           changes[s[right] -  a ][left] += sqrLen;         if (gray[len - 1][i] && countMidColor[half] - countMidColor[i] == 0)           changes[s[left] -  a ][right] += sqrLen;       }     }   }   bool solve() {     if (scanf( %s , s) < 1) return 0;     int n = strlen(s);     precalc(n);     long long ans = getInitial(n);     findChanges(n);     long long maxAdd = 0;     for (int i = 0; i < maxc; ++i)       for (int j = 0; j < n; ++j)         maxAdd = max(maxAdd, -wholeTaken[j] + changes[i][j]);     printf(          %lld            n ,         ans + maxAdd);     return 1;   }   int main() {     srand(rdtsc());     while (1) {       if (!solve()) break;     }     return 0;   }   