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Circular Palindromes
Circular Palindromes
+ 0 comments Here is Circular palindromes problem solution in Python Java C++ and C programming - https://programs.programmingoneonone.com/2021/07/hackerrank-circular-palindromes-problem-solution.html
+ 0 comments #include<bits/stdc++.h> using namespace std; #define REP(i,a,b) for(i=a;i<b;i++) #define rep(i,n) REP(i,0,n) #define mygc(c) (c)=getchar_unlocked() #define mypc(c) putchar_unlocked(c) #define ll long long #define ull unsigned ll void reader(int *x){int k,m=0;*x=0;for(;;){mygc(k);if(k=='-'){m=1;break;}if('0'<=k&&k<='9'){*x=k-'0';break;}}for(;;){mygc(k);if(k<'0'||k>'9')break;*x=(*x)*10+k-'0';}if(m)(*x)=-(*x);} void reader(ll *x){int k,m=0;*x=0;for(;;){mygc(k);if(k=='-'){m=1;break;}if('0'<=k&&k<='9'){*x=k-'0';break;}}for(;;){mygc(k);if(k<'0'||k>'9')break;*x=(*x)*10+k-'0';}if(m)(*x)=-(*x);} void reader(double *x){scanf("%lf",x);} int reader(char c[]){int i,s=0;for(;;){mygc(i);if(i!=' '&&i!='\n'&&i!='\r'&&i!='\t'&&i!=EOF) break;}c[s++]=i;for(;;){mygc(i);if(i==' '||i=='\n'||i=='\r'||i=='\t'||i==EOF) break;c[s++]=i;}c[s]='\0';return s;} template <class T, class S> void reader(T *x, S *y){reader(x);reader(y);} template <class T, class S, class U> void reader(T *x, S *y, U *z){reader(x);reader(y);reader(z);} template <class T, class S, class U, class V> void reader(T *x, S *y, U *z, V *w){reader(x);reader(y);reader(z);reader(w);} void writer(int x, char c){int s=0,m=0;char f[10];if(x<0)m=1,x=-x;while(x)f[s++]=x%10,x/=10;if(!s)f[s++]=0;if(m)mypc('-');while(s--)mypc(f[s]+'0');mypc(c);} void writer(ll x, char c){int s=0,m=0;char f[20];if(x<0)m=1,x=-x;while(x)f[s++]=x%10,x/=10;if(!s)f[s++]=0;if(m)mypc('-');while(s--)mypc(f[s]+'0');mypc(c);} void writer(double x, char c){printf("%.15f",x);mypc(c);} void writer(const char c[]){int i;for(i=0;c[i]!='\0';i++)mypc(c[i]);} void writer(const char x[], char c){int i;for(i=0;x[i]!='\0';i++)mypc(x[i]);mypc(c);} template<class T> void writerLn(T x){writer(x,'\n');} template<class T, class S> void writerLn(T x, S y){writer(x,' ');writer(y,'\n');} template<class T, class S, class U> void writerLn(T x, S y, U z){writer(x,' ');writer(y,' ');writer(z,'\n');} template<class T> void writerArr(T x[], int n){int i;if(!n){mypc('\n');return;}rep(i,n-1)writer(x[i],' ');writer(x[n-1],'\n');} template<class T> void sort(int N, T a[], void *mem = NULL){sort(a,a+N);} template<class T1, class T2> void sort(int N, T1 a[], T2 b[], void *mem){int i;pair<T1,T2> *r=(pair<T1, T2>*)mem;rep(i,N)r[i].first=a[i],r[i].second=b[i];sort(r,r+N);rep(i,N)a[i]=r[i].first,b[i]=r[i].second;} template<class T1, class T2, class T3> void sort(int N, T1 a[], T2 b[], T3 c[], void *mem){int i;pair<T1,pair<T2,T3> > *r=(pair<T1,pair<T2,T3> >*)mem;rep(i,N)r[i].first=a[i],r[i].second.first=b[i],r[i].second.second=c[i];sort(r,r+N);rep(i,N)a[i]=r[i].first,b[i]=r[i].second.first,c[i]=r[i].second.second;} template<class T1, class T2, class T3, class T4> void sort(int N, T1 a[], T2 b[], T3 c[], T4 d[], void *mem){int i;pair<pair<T1,T2>,pair<T3,T4> > *r=(pair<pair<T1,T2>,pair<T3,T4> >*)mem;rep(i,N)r[i].first.first=a[i],r[i].first.second=b[i],r[i].second.first=c[i],r[i].second.second=d[i];sort(r,r+N);rep(i,N)a[i]=r[i].first.first,b[i]=r[i].first.second,c[i]=r[i].second.first,d[i]=r[i].second.second;} char memarr[77000000]; void *mem = memarr; #define MD 1000000007 template<class T> struct rollingHash64{ int len; T *data; ull *sum, *rev, *pw; ull mul; ull getinv(ull a){ ull t,s=a,u=0,v=1,e; e = numeric_limits<ull>::max() / s; t -= e * s; u -= e * v; swap(t,s); swap(u,v); while(s){ e=t/s; t-=e*s; u-=e*v; swap(t,s); swap(u,v); } return u; } void* init(int n, T *arr, ull m = 0, void *mem = NULL){ int i; ull v; mul = m; if(mul==0) mul = 2*(rand()%1000000000) + 1000000001ULL; len = n; data = arr; if(mem == NULL){ pw = (ull*)malloc(sizeof(ull)*(2*len+1)); sum = (ull*)malloc(sizeof(ull)*(len+1)); rev = (ull*)malloc(sizeof(ull)*(len+1)); } else { pw = (ull*)mem; sum = pw + 2*len + 1; rev = sum + len + 1; mem = rev + len + 1; } v = getinv(mul); pw = pw + len; pw[0] = 1; rep(i,len) pw[ i+1] = pw[ i] * mul; rep(i,len) pw[-i-1] = pw[-i] * v; sum[0] = 0; rep(i,len) sum[i+1] = sum[i] + (ull)data[i] * pw[i]; rev[len] = 0; for(i=len-1;i>=0;i--) rev[i] = rev[i+1] + (ull)data[i] * pw[len-i-1]; return mem; } ull get(int a, int b, int off=0){ ull res; if(a <= b){ res = (sum[b+1] - sum[a]) * pw[-a+off] + (b-a+1); } else { res = (rev[b] - rev[a+1]) * pw[-(len-1-a)+off] + (a-b+1); } return res; } }; template<class T> void manacher(int n, T arr[], int res[]) { int i, j, k; for(i=0,j=0; i<2*n; i+=k, j=max(j-k,0)) { while(i-j >= 0 && i+j+1 < 2*n && arr[(i-j)/2] == arr[(i+j+1)/2]) ++j; res[i] = j; for(k=1; i-k >= 0 && res[i]-k >= 0 && res[i-k] != res[i]-k; ++k) res[i+k] = min(res[i-k], res[i]-k); } } template<class T> struct lazySegtreeMinVal{ int N, logN; T *data; T *fixval; char *fixed; T *addval; void malloc(int maxN){ int i; for(i=1;i<maxN;i*=2); data = (T*)std::malloc(sizeof(T)*2*i); fixval = (T*)std::malloc(sizeof(T)*i); addval = (T*)std::malloc(sizeof(T)*i); fixed = (char*)std::malloc(sizeof(char)*i); } T& operator[](int i){ return data[N+i]; } void setN(int n, int zerofill = 1){ int i; for(i=1,logN=0;i<n;i*=2,logN++); N = i; if(zerofill) rep(i,N) data[N+i] = 0; } void build(void){ int i; for(i=N-1;i;i--) data[i] = min(data[2*i],data[2*i+1]); REP(i,1,N) fixed[i] = 0; REP(i,1,N) addval[i] = 0; } inline void push_one(int a, int sz){ if(fixed[a]){ if(sz > 1){ fixed[a*2] = fixed[a*2+1] = 1; fixval[a*2] = fixval[a*2+1] = fixval[a]; data[a*2] = data[a*2+1] = fixval[a]; } else { data[a*2] = data[a*2+1] = fixval[a]; } fixed[a] = 0; addval[a] = 0; return; } if(addval[a] != 0){ if(sz > 1){ if(fixed[a*2]) fixval[a*2] += addval[a]; else addval[a*2] += addval[a]; if(fixed[a*2+1]) fixval[a*2+1] += addval[a]; else addval[a*2+1] += addval[a]; data[a*2] += addval[a]; data[a*2+1] += addval[a]; } else { data[a*2] += addval[a]; data[a*2+1] += addval[a]; } addval[a] = 0; return; } } inline void push(int a){ int i, aa; for(i=logN;i;i--){ aa = a>>i; push_one(aa, 1<<(i-1)); } } inline void build(int a){ while(a > 1){ a /= 2; if(fixed[a]){ data[a] = fixval[a]; } else { data[a] = min(data[a*2], data[a*2+1]); if(addval[a] != 0) data[a] += addval[a]; } } } inline void change(int a, int b, T val){ int aa, bb; if(a >= b) return; aa = (a += N); bb = (b += N); push(a); push(b-1); if(a%2) data[a++] = val; if(b%2) data[--b] = val; a /= 2; b /= 2; while(a < b){ if(a%2) fixed[a]=1, fixval[a]=val, data[a++] = val; if(b%2) fixed[--b]=1, fixval[b]=val, data[b] = val; a /= 2; b /= 2; } build(aa); build(bb-1); } inline void add(int a, int b, T val){ int sz = 1, aa, bb; if(a >= b) return; aa = (a += N); bb = (b += N); push(a); push(b-1); if(a%2) data[a++] += val; if(b%2) data[--b] += val; a /= 2; b /= 2; while(a < b){ sz *= 2; if(a%2){ if(fixed[a]) fixval[a] += val; else addval[a] += val; data[a++] += val; } if(b%2){ b--; if(fixed[b]) fixval[b] += val; else addval[b] += val; data[b] += val; } a /= 2; b /= 2; } build(aa); build(bb-1); } inline T getMinVal(int a, int b){ T res; int sz = 1; a += N; b += N; push(a); push(b-1); res = std::numeric_limits<T>::max(); while(a < b){ if(a%2) res = min(res, data[a++]); if(b%2) res = min(res, data[--b]); a /= 2; b /= 2; } return res; } }; int N; char S[2000000]; int rad[3000000]; int res[1000000]; int ss[3000000], ee[3000000], vv[3000000], nx[1000000]; int get_nx(int i){ if(nx[i]==-1) return i; if(i==N-1) return nx[i] = N; return nx[i] = get_nx(nx[i]); } int main(){ int i, j, k, st, ed, m, d; // rollingHash64<char> h; // lazySegtreeMinVal<int> t; reader(&N,S); // h.init(N,S); // t.malloc(N); // t.setN(N); // t.build(); rep(i,N) S[N+i] = S[i]; manacher(2*N, S, rad); rep(i,4*N){ k = min(N,rad[i]); if(i%2==0 && k%2==0) k--; if(i%2==1 && k%2==1) k--; if(rad[i]==0) continue; st = i/2 - (k-1)/2; ed = i/2 + k/2; m = ed-st+1; ss[i] = (st-(N-m)+N+N)%N; ee[i] = (st+N+N)%N; vv[i] = m; // rep(j,N-m+1) res[(st+N-j)%N] = max(res[(st+N-j)%N], m); } sort(4*N, vv, ss, ee, mem); rep(i,N+1) nx[i] = -1; for(i=4*N-1;i>=0;i--){ if(ss[i] <= ee[i]){ k = ss[i]; while(k <= ee[i]){ // writerLn(ss[i],k,ee[i]); res[k] = max(res[k], vv[i]); if(nx[k]==-1) nx[k] = k+1; k = get_nx(k); } } else { k = ss[i]; while(k < N){ // writerLn(ss[i],k,N); res[k] = max(res[k], vv[i]); if(nx[k]==-1) nx[k] = k+1; k = get_nx(k); } k = 0; while(k <= ee[i]){ // writerLn(0,k,ee[i]); res[k] = max(res[k], vv[i]); if(nx[k]==-1) nx[k] = k+1; k = get_nx(k); } } } REP(i,1,2*N) res[i%N] = max(res[i%N], res[(i-1)%N]-2); for(i=2*N-2;i>=0;i--) res[i%N] = max(res[i%N], res[(i+1)%N]-2); rep(i,N) writerLn(res[i]); return 0; }
+ 0 comments https://zeroplusfour.com/circular-palindromes/
Here's how I did in all languages Java 8 , C++ , C , Python 3, Python 2.
+ 1 comment In this explaination, explained the string "cacbbba" with max substring as '3' only. But there is a combination "acbbbca" which is with max 7. It is not covered
+ 0 comments import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.Arrays; import java.util.InputMismatchException;
public class E2 { InputStream is; PrintWriter out; String INPUT = "";
void solve() { int n = ni(); char[] s = ns(n); char[] s2 = new char[2*n]; for(int i = 0;i < n;i++){ s2[i] = s2[i+n] = s[i]; } int[] pal = palindrome(s2);
// tr(pal, pal.length, n); long[] es = new long[16*n]; int p = 0; for(int i = 0;i < 4*n;i+=2){ pal[i] = Math.min(pal[i], n-((n&1)^1)); es[p++] = (long)(i/2)<<32|i; es[p++] = (long)(i/2+pal[i]/2)<<32|i; es[p++] = (long)(i/2+n-pal[i]/2-1)<<32|i; es[p++] = (long)(i/2+n)<<32|i; } for(int i = 1;i < 4*n;i+=2){ pal[i] = Math.min(pal[i], n-((n&1))); es[p++] = (long)(i/2)<<32|i; es[p++] = (long)(i/2+pal[i]/2)<<32|i; es[p++] = (long)(i/2+n-pal[i]/2)<<32|i; es[p++] = (long)(i/2+n)<<32|i; }
Arrays.sort(es, 0, p); MaxHeap inc = new MaxHeap(4*n+1); MaxHeap dec = new MaxHeap(4*n+1); MaxHeap flat = new MaxHeap(4*n+1); int[] st = new int[4*n]; int q = 0; for(int i = 0;i < 2*n-1;i++){ while(q < p && es[q]>>>32 <= i){ int ind = (int)es[q]; if(st[ind] == 0){ inc.add(ind, (pal[ind]&1)-2*i); }else if(st[ind] == 1){ inc.remove(ind); flat.add(ind, pal[ind]); }else if(st[ind] == 2){ flat.remove(ind); dec.add(ind, pal[ind]+2*i); }else if(st[ind] == 3){ dec.remove(ind); } st[ind]++; q++; } if(i >= n-1){
// tr("i", i); int max = 0; if(inc.size() > 0)max = Math.max(inc.max()+2*i, max); // tr(max); if(dec.size() > 0)max = Math.max(dec.max()-2*i, max); // tr(max); max = Math.max(flat.max(), max); // tr(max); out.println(max); } } } public static class MaxHeap { public int[] a; public int[] map; public int[] imap; public int n; public int pos; public static int INF = Integer.MIN_VALUE;
public MaxHeap(int m) { n = m+2; a = new int[n]; map = new int[n]; imap = new int[n]; Arrays.fill(a, INF); Arrays.fill(map, -1); Arrays.fill(imap, -1); pos = 1; } public int add(int ind, int x) { int ret = imap[ind]; if(imap[ind] < 0){ a[pos] = x; map[pos] = ind; imap[ind] = pos; pos++; up(pos-1); } return ret != -1 ? a[ret] : x; } public int update(int ind, int x) { int ret = imap[ind]; if(imap[ind] < 0){ a[pos] = x; map[pos] = ind; imap[ind] = pos; pos++; up(pos-1); }else{ int o = a[ret]; a[ret] = x; up(ret); down(ret);
// if(a[ret] < o){ // up(ret); // }else{ // down(ret); // } } return x; }
public int remove(int ind) { if(pos == 1)return INF; if(imap[ind] == -1)return INF; pos--; int rem = imap[ind]; int ret = a[rem]; map[rem] = map[pos]; imap[map[pos]] = rem; imap[ind] = -1; a[rem] = a[pos]; a[pos] = INF; map[pos] = -1; up(rem); down(rem); return ret; } public int max() { return a[1]; } public int argmax() { return map[1]; } public int size() { return pos-1; } private void up(int cur) { for(int c = cur, p = c>>>1;p >= 1 && a[p] < a[c];c>>>=1, p>>>=1){ int d = a[p]; a[p] = a[c]; a[c] = d; int e = imap[map[p]]; imap[map[p]] = imap[map[c]]; imap[map[c]] = e; e = map[p]; map[p] = map[c]; map[c] = e; } } private void down(int cur) { for(int c = cur;2*c < pos;){ int b = a[2*c] > a[2*c+1] ? 2*c : 2*c+1; if(a[b] > a[c]){ int d = a[c]; a[c] = a[b]; a[b] = d; int e = imap[map[c]]; imap[map[c]] = imap[map[b]]; imap[map[b]] = e; e = map[c]; map[c] = map[b]; map[b] = e; c = b; }else{ break; } } } } public static int[] palindrome(char[] str) { int n = str.length; int[] r = new int[2*n]; int k = 0; for(int i = 0, j = 0;i < 2*n;i += k, j = Math.max(j-k, 0)){ // normally while(i-j >= 0 && i+j+1 < 2*n && str[(i-j)/2] == str[(i+j+1)/2])j++; r[i] = j; // skip based on the theorem for(k = 1;i-k >= 0 && r[i]-k >= 0 && r[i-k] != r[i]-k;k++){ r[i+k] = Math.min(r[i-k], r[i]-k); } } return r; } void run() throws Exception { is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()); out = new PrintWriter(System.out); long s = System.currentTimeMillis(); solve(); out.flush(); if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); } public static void main(String[] args) throws Exception { new E2().run(); } private byte[] inbuf = new byte[1024]; private int lenbuf = 0, ptrbuf = 0; private int readByte() { if(lenbuf == -1)throw new InputMismatchException(); if(ptrbuf >= lenbuf){ ptrbuf = 0; try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); } if(lenbuf <= 0)return -1; } return inbuf[ptrbuf++]; } private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } private double nd() { return Double.parseDouble(ns()); } private char nc() { return (char)skip(); } private String ns() { int b = skip(); StringBuilder sb = new StringBuilder(); while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ') sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } private char[] ns(int n) { char[] buf = new char[n]; int b = skip(), p = 0; while(p < n && !(isSpaceChar(b))){ buf[p++] = (char)b; b = readByte(); } return n == p ? buf : Arrays.copyOf(buf, p); } private char[][] nm(int n, int m) { char[][] map = new char[n][]; for(int i = 0;i < n;i++)map[i] = ns(m); return map; } private int[] na(int n) { int[] a = new int[n]; for(int i = 0;i < n;i++)a[i] = ni(); return a; } private int ni() { int num = 0, b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private long nl() { long num = 0; int b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}
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