TEST -33
LINK:
https://www.hackerrank.com/ececodetest33
1]
Gridland Provinces
#include <stdio.h>
#include <stdlib.h>
#define MOD1 1000000007
#define MOD2 1000000009
#define HASH_SIZE 123455
typedef struct _node{
int x;
int y;
struct _node *next;
} node;
void solve(int i,int j);
void insert(int x,int y);
void freehash();
long long modInverse(long long a,long long mod);
char a[2][601];
int hash_count,N;
long long tr1[1200],tl1[1200],br1[1200],bl1[1200],dr1[1200],dl1[1200],ur1[1200],ul1[1200],mod1[1201],inmod1[1201];
long long tr2[1200],tl2[1200],br2[1200],bl2[1200],dr2[1200],dl2[1200],ur2[1200],ul2[1200],mod2[1201],inmod2[1201];
node *hash[HASH_SIZE]={0};
int main(){
int T,i,j;
long long t1,t2;
scanf("%d",&T);
while(T--){
hash_count=0;
scanf("%d%s%s",&N,&a[0][0],&a[1][0]);
for(i=0,t1=t2=1;i<N;i++,t1=t1*26%MOD1,t2=t2*26%MOD2)
if(i){
tl1[i]=((a[0][i]-'a')*t1+tl1[i-1])%MOD1;
bl1[i]=((a[1][i]-'a')*t1+bl1[i-1])%MOD1;
tl2[i]=((a[0][i]-'a')*t2+tl2[i-1])%MOD2;
bl2[i]=((a[1][i]-'a')*t2+bl2[i-1])%MOD2;
}
else{
tl1[i]=a[0][i]-'a';
bl1[i]=a[1][i]-'a';
tl2[i]=a[0][i]-'a';
bl2[i]=a[1][i]-'a';
}
for(i=N-1;i>=0;i--,t1=t1*26%MOD1,t2=t2*26%MOD2){
tl1[2*N-i-1]=((a[1][i]-'a')*t1+tl1[2*N-i-2])%MOD1;
bl1[2*N-i-1]=((a[0][i]-'a')*t1+bl1[2*N-i-2])%MOD1;
tl2[2*N-i-1]=((a[1][i]-'a')*t2+tl2[2*N-i-2])%MOD2;
bl2[2*N-i-1]=((a[0][i]-'a')*t2+bl2[2*N-i-2])%MOD2;
}
for(i=N-1,t1=t2=1;i>=0;i--,t1=t1*26%MOD1,t2=t2*26%MOD2)
if(i!=N-1){
tr1[N-i-1]=((a[0][i]-'a')*t1+tr1[N-i-2])%MOD1;
br1[N-i-1]=((a[1][i]-'a')*t1+br1[N-i-2])%MOD1;
tr2[N-i-1]=((a[0][i]-'a')*t2+tr2[N-i-2])%MOD2;
br2[N-i-1]=((a[1][i]-'a')*t2+br2[N-i-2])%MOD2;
}
else{
tr1[N-i-1]=a[0][i]-'a';
br1[N-i-1]=a[1][i]-'a';
tr2[N-i-1]=a[0][i]-'a';
br2[N-i-1]=a[1][i]-'a';
}
for(i=0;i<N;i++,t1=t1*26%MOD1,t2=t2*26%MOD2){
tr1[i+N]=((a[1][i]-'a')*t1+tr1[i+N-1])%MOD1;
br1[i+N]=((a[0][i]-'a')*t1+br1[i+N-1])%MOD1;
tr2[i+N]=((a[1][i]-'a')*t2+tr2[i+N-1])%MOD2;
br2[i+N]=((a[0][i]-'a')*t2+br2[i+N-1])%MOD2;
}
for(i=0,t1=t2=1;i<N;i++){
if(i%2){
ul1[2*i]=((a[0][i]-'a')*t1+ul1[2*i-1])%MOD1;
dl1[2*i]=((a[1][i]-'a')*t1+dl1[2*i-1])%MOD1;
ul2[2*i]=((a[0][i]-'a')*t2+ul2[2*i-1])%MOD2;
dl2[2*i]=((a[1][i]-'a')*t2+dl2[2*i-1])%MOD2;
}
else
if(!i){
ul1[2*i]=a[1][i]-'a';
dl1[2*i]=a[0][i]-'a';
ul2[2*i]=a[1][i]-'a';
dl2[2*i]=a[0][i]-'a';
}
else{
ul1[2*i]=((a[1][i]-'a')*t1+ul1[2*i-1])%MOD1;
dl1[2*i]=((a[0][i]-'a')*t1+dl1[2*i-1])%MOD1;
ul2[2*i]=((a[1][i]-'a')*t2+ul2[2*i-1])%MOD2;
dl2[2*i]=((a[0][i]-'a')*t2+dl2[2*i-1])%MOD2;
}
t1=t1*26%MOD1;
t2=t2*26%MOD2;
if(i%2){
ul1[2*i+1]=((a[1][i]-'a')*t1+ul1[2*i])%MOD1;
dl1[2*i+1]=((a[0][i]-'a')*t1+dl1[2*i])%MOD1;
ul2[2*i+1]=((a[1][i]-'a')*t2+ul2[2*i])%MOD2;
dl2[2*i+1]=((a[0][i]-'a')*t2+dl2[2*i])%MOD2;
}
else{
ul1[2*i+1]=((a[0][i]-'a')*t1+ul1[2*i])%MOD1;
dl1[2*i+1]=((a[1][i]-'a')*t1+dl1[2*i])%MOD1;
ul2[2*i+1]=((a[0][i]-'a')*t2+ul2[2*i])%MOD2;
dl2[2*i+1]=((a[1][i]-'a')*t2+dl2[2*i])%MOD2;
}
t1=t1*26%MOD1;
t2=t2*26%MOD2;
}
for(i=N-1,t1=t2=1;i>=0;i--)
if(i==N-1){
ur1[2*(N-1-i)]=a[1][i]-'a';
dr1[2*(N-1-i)]=a[0][i]-'a';
ur2[2*(N-1-i)]=a[1][i]-'a';
dr2[2*(N-1-i)]=a[0][i]-'a';
t1=t1*26%MOD1;
t2=t2*26%MOD2;
ur1[2*(N-1-i)+1]=((a[0][i]-'a')*t1+ur1[2*(N-1-i)])%MOD1;
dr1[2*(N-1-i)+1]=((a[1][i]-'a')*t1+dr1[2*(N-1-i)])%MOD1;
ur2[2*(N-1-i)+1]=((a[0][i]-'a')*t2+ur2[2*(N-1-i)])%MOD2;
dr2[2*(N-1-i)+1]=((a[1][i]-'a')*t2+dr2[2*(N-1-i)])%MOD2;
t1=t1*26%MOD1;
t2=t2*26%MOD2;
}
else{
if((N-i)%2==0){
ur1[2*(N-1-i)]=((a[0][i]-'a')*t1+ur1[2*(N-1-i)-1])%MOD1;
dr1[2*(N-1-i)]=((a[1][i]-'a')*t1+dr1[2*(N-1-i)-1])%MOD1;
ur2[2*(N-1-i)]=((a[0][i]-'a')*t2+ur2[2*(N-1-i)-1])%MOD2;
dr2[2*(N-1-i)]=((a[1][i]-'a')*t2+dr2[2*(N-1-i)-1])%MOD2;
}
else{
ur1[2*(N-1-i)]=((a[1][i]-'a')*t1+ur1[2*(N-1-i)-1])%MOD1;
dr1[2*(N-1-i)]=((a[0][i]-'a')*t1+dr1[2*(N-1-i)-1])%MOD1;
ur2[2*(N-1-i)]=((a[1][i]-'a')*t2+ur2[2*(N-1-i)-1])%MOD2;
dr2[2*(N-1-i)]=((a[0][i]-'a')*t2+dr2[2*(N-1-i)-1])%MOD2;
}
t1=t1*26%MOD1;
t2=t2*26%MOD2;
if((N-i)%2==0){
ur1[2*(N-1-i)+1]=((a[1][i]-'a')*t1+ur1[2*(N-1-i)])%MOD1;
dr1[2*(N-1-i)+1]=((a[0][i]-'a')*t1+dr1[2*(N-1-i)])%MOD1;
ur2[2*(N-1-i)+1]=((a[1][i]-'a')*t2+ur2[2*(N-1-i)])%MOD2;
dr2[2*(N-1-i)+1]=((a[0][i]-'a')*t2+dr2[2*(N-1-i)])%MOD2;
}
else{
ur1[2*(N-1-i)+1]=((a[0][i]-'a')*t1+ur1[2*(N-1-i)])%MOD1;
dr1[2*(N-1-i)+1]=((a[1][i]-'a')*t1+dr1[2*(N-1-i)])%MOD1;
ur2[2*(N-1-i)+1]=((a[0][i]-'a')*t2+ur2[2*(N-1-i)])%MOD2;
dr2[2*(N-1-i)+1]=((a[1][i]-'a')*t2+dr2[2*(N-1-i)])%MOD2;
}
t1=t1*26%MOD1;
t2=t2*26%MOD2;
}
for(i=0;i<=2*N;i++)
if(i){
mod1[i]=mod1[i-1]*26%MOD1;
inmod1[i]=modInverse(mod1[i],MOD1);
mod2[i]=mod2[i-1]*26%MOD2;
inmod2[i]=modInverse(mod2[i],MOD2);
}
else
mod1[i]=inmod1[i]=mod2[i]=inmod2[i]=1;
for(i=0;i<=N;i++)
for(j=i;j<=N;j++)
solve(i,j);
printf("%d\n",hash_count);
freehash();
}
return 0;
}
void solve(int i,int j){
long long t1,t2,t3,t4,t5,t6,t7,t8,t9;
long long tt1,tt2,tt3,tt4,tt5,tt6,tt7,tt8,tt9;
t1=tr1[N+i-1];
t2=br1[N+i-1];
if(i!=N){
t1=(t1-tr1[N-i-1]+MOD1)%MOD1;
t2=(t2-br1[N-i-1]+MOD1)%MOD1;
}
t1=t1*inmod1[N-i]%MOD1;
t2=t2*inmod1[N-i]%MOD1;
t3=tl1[2*N-j-1];
t4=bl1[2*N-j-1];
if(j){
t3=(t3-tl1[j-1]+MOD1)%MOD1;
t4=(t4-bl1[j-1]+MOD1)%MOD1;
}
t3=t3*inmod1[j]%MOD1;
t4=t4*inmod1[j]%MOD1;
if(!j)
t5=t6=0;
else{
t5=ul1[2*j-1];
t6=dl1[2*j-1];
if(i){
t5=(t5-ul1[2*i-1]+MOD1)%MOD1;
t6=(t6-dl1[2*i-1]+MOD1)%MOD1;
}
}
if(i==N)
t7=t8=0;
else{
t7=ur1[2*(N-i)-1];
t8=dr1[2*(N-i)-1];
if(j!=N){
t7=(t7-ur1[2*(N-j)-1]+MOD1)%MOD1;
t8=(t8-dr1[2*(N-j)-1]+MOD1)%MOD1;
}
}
tt1=tr2[N+i-1];
tt2=br2[N+i-1];
if(i!=N){
tt1=(tt1-tr2[N-i-1]+MOD2)%MOD2;
tt2=(tt2-br2[N-i-1]+MOD2)%MOD2;
}
tt1=tt1*inmod2[N-i]%MOD2;
tt2=tt2*inmod2[N-i]%MOD2;
tt3=tl2[2*N-j-1];
tt4=bl2[2*N-j-1];
if(j){
tt3=(tt3-tl2[j-1]+MOD2)%MOD2;
tt4=(tt4-bl2[j-1]+MOD2)%MOD2;
}
tt3=tt3*inmod2[j]%MOD2;
tt4=tt4*inmod2[j]%MOD2;
if(!j)
tt5=tt6=0;
else{
tt5=ul2[2*j-1];
tt6=dl2[2*j-1];
if(i){
tt5=(tt5-ul2[2*i-1]+MOD2)%MOD2;
tt6=(tt6-dl2[2*i-1]+MOD2)%MOD2;
}
}
if(i==N)
tt7=tt8=0;
else{
tt7=ur2[2*(N-i)-1];
tt8=dr2[2*(N-i)-1];
if(j!=N){
tt7=(tt7-ur2[2*(N-j)-1]+MOD2)%MOD2;
tt8=(tt8-dr2[2*(N-j)-1]+MOD2)%MOD2;
}
}
t9=t1;
if(i%2)
t9+=t6;
else
t9+=t5;
if((j-i)%2)
t9+=t3*mod1[j*2]%MOD1;
else
t9+=t4*mod1[j*2]%MOD1;
t9%=MOD1;
tt9=tt1;
if(i%2)
tt9+=tt6;
else
tt9+=tt5;
if((j-i)%2)
tt9+=tt3*mod2[j*2]%MOD2;
else
tt9+=tt4*mod2[j*2]%MOD2;
tt9%=MOD2;
insert(t9,tt9);
t9=t2;
if(i%2)
t9+=t5;
else
t9+=t6;
if((j-i)%2)
t9+=t4*mod1[j*2]%MOD1;
else
t9+=t3*mod1[j*2]%MOD1;
t9%=MOD1;
tt9=tt2;
if(i%2)
tt9+=tt5;
else
tt9+=tt6;
if((j-i)%2)
tt9+=tt4*mod2[j*2]%MOD2;
else
tt9+=tt3*mod2[j*2]%MOD2;
tt9%=MOD2;
insert(t9,tt9);
t9=t3;
if((N-j)%2)
t9+=t8;
else
t9+=t7;
if((j-i)%2)
t9+=t1*mod1[(N-i)*2]%MOD1;
else
t9+=t2*mod1[(N-i)*2]%MOD1;
t9%=MOD1;
tt9=tt3;
if((N-j)%2)
tt9+=tt8;
else
tt9+=tt7;
if((j-i)%2)
tt9+=tt1*mod2[(N-i)*2]%MOD2;
else
tt9+=tt2*mod2[(N-i)*2]%MOD2;
tt9%=MOD2;
insert(t9,tt9);
t9=t4;
if((N-j)%2)
t9+=t7;
else
t9+=t8;
if((j-i)%2)
t9+=t2*mod1[(N-i)*2]%MOD1;
else
t9+=t1*mod1[(N-i)*2]%MOD1;
t9%=MOD1;
tt9=tt4;
if((N-j)%2)
tt9+=tt7;
else
tt9+=tt8;
if((j-i)%2)
tt9+=tt2*mod2[(N-i)*2]%MOD2;
else
tt9+=tt1*mod2[(N-i)*2]%MOD2;
tt9%=MOD2;
insert(t9,tt9);
return;
}
void insert(int x,int y){
int bucket=(x+y)%HASH_SIZE;
node *t=hash[bucket];
while(t){
if(t->x==x && t->y==y)
return;
t=t->next;
}
t=(node*)malloc(sizeof(node));
t->x=x;
t->y=y;
t->next=hash[bucket];
hash[bucket]=t;
hash_count++;
return;
}
void freehash(){
int i;
node *t,*p;
for(i=0;i<HASH_SIZE;i++){
t=hash[i];
while(t){
p=t->next;
free(t);
t=p;
}
hash[i]=NULL;
}
return;
}
long long modInverse(long long a,long long mod){
long long b0 = mod, t, q;
long long x0 = 0, x1 = 1;
while (a > 1) {
q = a / mod;
t = mod; mod = a % mod; a = t;
t = x0; x0 = x1 - q * x0; x1 = t;
}
if (x1 < 0) x1 += b0;
return x1;
}
2]
Ashton and String
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#define N 100001
void merge(int*a,int*left,int*right,int left_size, int right_size);
void sort_a(int*a,int size);
void suffixSort(int n);
void LCP(int n);
char str[N]; //input
int rank[N], pos[N], lcp[N]; //output
int cnt[N], next[N]; //internal
int bh[N], b2h[N];
int main(){
char cc;
int T,n,i;
long long K,c,t,x,tt;
double xx;
scanf("%d",&T);
while(T--){
scanf("%s%lld",str,&K);
n=strlen(str);
suffixSort(n);
LCP(n);
c=0;
for(i=0;i<n;i++){
tt=c;
c+=(lcp[i]+1+n-pos[i])*(long long)(n-pos[i]-lcp[i])/2;
if(K<=c){
xx=(-1+sqrt(4*(2*(K-tt)+lcp[i]+lcp[i]*(long long)lcp[i])))/2;
x=(long long)xx;
t=K-tt-(lcp[i]+1+x)*(x-lcp[i])/2;
if(!t)
cc=str[pos[i]+x-1];
else
cc=str[pos[i]+t-1];
break;
}
}
printf("%c\n",cc);
}
return 0;
}
void merge(int*a,int*left,int*right,int left_size, int right_size){
int i = 0, j = 0;
while (i < left_size|| j < right_size) {
if (i == left_size) {
a[i+j] = right[j];
j++;
} else if (j == right_size) {
a[i+j] = left[i];
i++;
} else if (str[left[i]] <= str[right[j]]) {
a[i+j] = left[i];
i++;
} else {
a[i+j] = right[j];
j++;
}
}
return;
}
void sort_a(int*a,int size){
if (size < 2)
return;
int m = (size+1)/2,i;
int *left,*right;
left=(int*)malloc(m*sizeof(int));
right=(int*)malloc((size-m)*sizeof(int));
for(i=0;i<m;i++)
left[i]=a[i];
for(i=0;i<size-m;i++)
right[i]=a[i+m];
sort_a(left,m);
sort_a(right,size-m);
merge(a,left,right,m,size-m);
free(left);
free(right);
return;
}
void suffixSort(int n){
//sort suffixes according to their first characters
int h,i,j,k;
for (i=0; i<n; ++i){
pos[i] = i;
}
sort_a(pos, n);
//{pos contains the list of suffixes sorted by their first character}
for (i=0; i<n; ++i){
bh[i] = i == 0 || str[pos[i]] != str[pos[i-1]];
b2h[i] = 0;
}
for (h = 1; h < n; h <<= 1){
//{bh[i] == false if the first h characters of pos[i-1] == the first h characters of pos[i]}
int buckets = 0;
for (i=0; i < n; i = j){
j = i + 1;
while (j < n && !bh[j]) j++;
next[i] = j;
buckets++;
}
if (buckets == n) break; // We are done! Lucky bastards!
//{suffixes are separted in buckets containing strings starting with the same h characters}
for (i = 0; i < n; i = next[i]){
cnt[i] = 0;
for (j = i; j < next[i]; ++j){
rank[pos[j]] = i;
}
}
cnt[rank[n - h]]++;
b2h[rank[n - h]] = 1;
for (i = 0; i < n; i = next[i]){
for (j = i; j < next[i]; ++j){
int s = pos[j] - h;
if (s >= 0){
int head = rank[s];
rank[s] = head + cnt[head]++;
b2h[rank[s]] = 1;
}
}
for (j = i; j < next[i]; ++j){
int s = pos[j] - h;
if (s >= 0 && b2h[rank[s]]){
for (k = rank[s]+1; !bh[k] && b2h[k]; k++) b2h[k] = 0;
}
}
}
for (i=0; i<n; ++i){
pos[rank[i]] = i;
bh[i] |= b2h[i];
}
}
for (i=0; i<n; ++i){
rank[pos[i]] = i;
}
}
// End of suffix array algorithm
void LCP(int n){
int l=0,i,j,k;
for(i=0;i<n;i++){
k=rank[i];
if(!k)
continue;
j=pos[k-1];
while(str[i+l]==str[j+l])
l++;
lcp[k]=l;
if(l>0)
l--;
}
lcp[0]=0;
return;
}
c++
3]
3]
Two Strings Game
#include<cstdio>
#include<map>
#include<set>
#include<bitset>
#include<string>
#include<cassert>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
typedef long long unsigned ull;
const ull inf = 1ull<<60;
const int N = 1203333,M=28;
struct state{
int len,link;
int next[26];
} sa[N];
int sg[N];
ull cnt[N][M],tot[N];
static int pmem=1;
int new_root(){
sa[pmem].len = 0;
sa[pmem].link = -1;
return pmem++;
}
void extend(int root,int& last,char c){
int np=pmem++,p=last;
sa[p].len=sa[last].len+1;
for(;~p && !sa[p].next[c];p=sa[p].link)sa[p].next[c]=np;
if(p==-1)sa[np].link=root;
else{int q=sa[p].next[c];
if(sa[p].len+1==sa[q].len)sa[np].link=q;
else{int nq=pmem++;
sa[nq].len=sa[p].len+1;
copy(sa[q].next,sa[q].next+26,sa[nq].next);
sa[nq].link=sa[q].link;
for(;~p&&sa[p].next[c]==q;p=sa[p].link)
sa[p].next[c]=nq;
sa[q].link=sa[np].link = nq;
}
}
last=np;
}
int dfs(int u){
int &ret=sg[u];
if(~ret)return ret;
bitset<M> mex;
tot[u]=1;
for(int i=0,v;i<26;++i)
if(v=sa[u].next[i]){
int t=dfs(v);
assert(t>=0 && t<M);
mex.set(t);
tot[u]+=tot[v];
for(int i=0;i<M;++i) cnt[u][i]+=cnt[v][i];
}
for(ret=0;mex.test(ret);++ret);
++cnt[u][ret];
assert(ret<M);
return ret;
}
struct dfs_st{int u,i;};
void manualdfs(int r){
vector<dfs_st> st;
for(st.push_back({r,0});!st.empty();){
int u=st.back().u,v;
if(st.back().i==26){
int mex=0;
tot[u]=1;
for(int i=0;i<26;++i)
if(v=sa[u].next[i]){
mex|=1<<sg[v];
tot[u]+=tot[v];
for(int j=0;j<M;++j)cnt[u][j]+=cnt[v][j];
}
for(sg[u]=0;mex>>sg[u] &1;++sg[u]);
++cnt[u][sg[u]];
st.pop_back();
}else
if((v=sa[u].next[st.back().i++])&& !~sg[v])
st.push_back({v,0});
}
}
ull mul(ull a,ull b){
return (b==0||a<inf/b)?a*b:inf;
}
int main(){
int l1,l2;
ull K;
int root1,last1,root2,last2;
scanf("%d%d%llu",&l1,&l2,&K);
getchar();
root1=last1=new_root();
for(int i=0;i<l1;++i)extend(root1,last1,getchar()-'a');
fill(sg+root1,sg+pmem,-1);
//dfs(root1);
manualdfs(root1);
getchar();
root2=last2=new_root();
for(int i=0;i<l2;++i)extend(root2,last2,getchar()-'a');
fill(sg+root2,sg+pmem,-1);
//dfs(root2);
manualdfs(root2);
string ans1,ans2;
int sg1= -1;
ull rcc[M];
for(int i=0;i<M;++i)rcc[i]=tot[root2]-cnt[root2][i];
ull tmp = 0;
for(int i=0;i<M && tmp<K;++i)
tmp+=mul(cnt[root1][i],rcc[i]);
if(tmp<K){
puts("no solution");
return 0;
}
for(int u=root1;;){
if(rcc[sg[u]]>=K){
sg1=sg[u];
puts(ans1.c_str());
break;
}
K-=rcc[sg[u]];
for(int i=0,v;i<26;++i)
if(v=sa[u].next[i]){
ull tmp= 0;
for(int i=0;i<M && tmp<K;++i)
tmp+=mul(cnt[v][i],rcc[i]);
if(tmp>=K){
ans1+=char('a'+i);
u=v;
break;
}
K-=tmp;
}
}
assert(rcc[sg1] >= K);
for(int u=root2;;){
if(K==1 && sg[u]!=sg1) {
puts(ans2.c_str());
return 0;
}
if(sg[u]!=sg1)--K;
for(int i=0,v;i<26;++i)
if(v=sa[u].next[i]){
ull tmp=0;
for(int j=0;j<M;++j)
if(j!=sg1) tmp+=cnt[v][j];
if(tmp>=K){
ans2+= char('a'+i);
u=v;
break;
}
K-=tmp;
}
}
