//Krzysztof Pieprzak #include <bits/stdc++.h> using namespace std; typedef long long ll; typedef long double ld; typedef unsigned long long ull; typedef unsigned int uint; typedef vector<int> vi; typedef vector<ll> vll; typedef pair<int,int> pii; typedef pair<long long, long long> pll; typedef vector<pii> vpii; typedef vector<pll> vpll; #define Size(x) (int)x.size() #define VAR(v,n) auto v = (n) #define FOR(i,a,b) for(VAR(i,a); i < (b); ++i) #define FORE(i,a,b) for(VAR(i,a); i <= (b); ++i) #define FORREV(i,a,b) for(VAR(i,b); i >= (a); --i) #define FORSTEP(i,a,b,step) for(VAR(i,a); i < (b); i += (step)) #define FOREACH(i,c) for(auto i : (c)) #define FOREACHS(i,c,n) for(VAR(i,&(c)[0]); i-(c)<(n); ++i) #define ALL(x) x.begin(),x.end() #define CLEAR(t) memset(t, 0, sizeof(t)) #define F first #define S second #define MP make_pair #define PUB push_back #define POB pop_back #define pieprzu ios_base::sync_with_stdio(0); const int INF = 1000000001; const double EPS = 10e-9; const int MAXN = 1000000; const int LETTERS = 3; const ll MAXK = 1000000000000000000LL; const int MAXK_LOG = 60; ll myPow[MAXK_LOG+10]; char word[MAXN+10]; void initPow() { myPow[0] = 1; FORE (i, 1, MAXK_LOG) { myPow[i] = myPow[i-1]*2; } } inline ll getWordsFixFirstLetter(int len) { return myPow[len] - 1; } inline ll getWords(int len) { return getWordsFixFirstLetter(len) * LETTERS; } bool check(int n, ll k) { if (n > 60) { return true; } return k <= getWords(n); } void createWord(int n, ll k) { int forbiddenLetter = -1; int pos = 0; while (k > 0) { if (n > MAXK_LOG) { word[pos] = forbiddenLetter == 0 ? 'b' : 'a'; --k; } else { ll sum = 0; FOR (letter, 0, LETTERS) { if (letter != forbiddenLetter) { if (k <= sum + getWordsFixFirstLetter(n)) { word[pos] = 'a' + letter; k -= sum+1; break; } sum += getWordsFixFirstLetter(n); } } } forbiddenLetter = word[pos]-'a'; ++pos; --n; } } void rob(int test) { int n; ll k; scanf("%d %lld", &n, &k); initPow(); if (!check(n, k)) { printf("NIE\n"); return; } createWord(n, k); printf("%s\n", word); } int main() { int test = 1; //scanf("%d", &test); FORE (i, 1, test) rob(i); return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 | //Krzysztof Pieprzak #include <bits/stdc++.h> using namespace std; typedef long long ll; typedef long double ld; typedef unsigned long long ull; typedef unsigned int uint; typedef vector<int> vi; typedef vector<ll> vll; typedef pair<int,int> pii; typedef pair<long long, long long> pll; typedef vector<pii> vpii; typedef vector<pll> vpll; #define Size(x) (int)x.size() #define VAR(v,n) auto v = (n) #define FOR(i,a,b) for(VAR(i,a); i < (b); ++i) #define FORE(i,a,b) for(VAR(i,a); i <= (b); ++i) #define FORREV(i,a,b) for(VAR(i,b); i >= (a); --i) #define FORSTEP(i,a,b,step) for(VAR(i,a); i < (b); i += (step)) #define FOREACH(i,c) for(auto i : (c)) #define FOREACHS(i,c,n) for(VAR(i,&(c)[0]); i-(c)<(n); ++i) #define ALL(x) x.begin(),x.end() #define CLEAR(t) memset(t, 0, sizeof(t)) #define F first #define S second #define MP make_pair #define PUB push_back #define POB pop_back #define pieprzu ios_base::sync_with_stdio(0); const int INF = 1000000001; const double EPS = 10e-9; const int MAXN = 1000000; const int LETTERS = 3; const ll MAXK = 1000000000000000000LL; const int MAXK_LOG = 60; ll myPow[MAXK_LOG+10]; char word[MAXN+10]; void initPow() { myPow[0] = 1; FORE (i, 1, MAXK_LOG) { myPow[i] = myPow[i-1]*2; } } inline ll getWordsFixFirstLetter(int len) { return myPow[len] - 1; } inline ll getWords(int len) { return getWordsFixFirstLetter(len) * LETTERS; } bool check(int n, ll k) { if (n > 60) { return true; } return k <= getWords(n); } void createWord(int n, ll k) { int forbiddenLetter = -1; int pos = 0; while (k > 0) { if (n > MAXK_LOG) { word[pos] = forbiddenLetter == 0 ? 'b' : 'a'; --k; } else { ll sum = 0; FOR (letter, 0, LETTERS) { if (letter != forbiddenLetter) { if (k <= sum + getWordsFixFirstLetter(n)) { word[pos] = 'a' + letter; k -= sum+1; break; } sum += getWordsFixFirstLetter(n); } } } forbiddenLetter = word[pos]-'a'; ++pos; --n; } } void rob(int test) { int n; ll k; scanf("%d %lld", &n, &k); initPow(); if (!check(n, k)) { printf("NIE\n"); return; } createWord(n, k); printf("%s\n", word); } int main() { int test = 1; //scanf("%d", &test); FORE (i, 1, test) rob(i); return 0; } |