/* Rozwiazanie na podstawie artykulu i kodu stad: https://www.geeksforgeeks.org/number-of-integers-in-a-range-l-r-which-are-divisible-by-exactly-k-of-its-digits/ */ #include <bits/stdc++.h> using namespace std; typedef long long int LL; const int LCM = 2520; const int MAX_MASK = (1 << 9) + 1; const int MAX_LEN = 19; LL l, r; LL states[MAX_LEN][2][LCM][MAX_MASK]; vector<int> digits; LL dp(const int idx, const int canZero, const int tight, const int rem, const int mask) { LL& res = states[idx][tight][rem][mask]; if(res != -1) { return res; } res = 0; if(idx == digits.size()) { int usedDigsCount = 0, divisibleByDigsCount = 0; for(int d = 1; d < 10; ++d) { if(mask & (1 << (d-1))) { ++usedDigsCount; if(rem % d == 0) { ++divisibleByDigsCount; } } } if(usedDigsCount == divisibleByDigsCount && usedDigsCount > 0) { res = 1; } } else { for(int d = (canZero ? 0 : 1); d < 10; ++d) { if(tight && d > digits[idx]) { continue; } const int newTight = ((tight == 1) ? (d == digits[idx]) : 0); const int newRem = (10*rem + d) % LCM; const int newCanZero = (canZero && (d == 0)); int newMask = mask; if(d != 0) { newMask = (mask | (1 << (d-1))); } res += dp(idx+1, newCanZero, newTight, newRem, newMask); } } return res; } LL findCount(LL x) { digits.clear(); while(x > 0) { digits.push_back(x%10); x /= 10; } reverse(digits.begin(), digits.end()); memset(states, -1, sizeof(states)); return dp(0, 1, 1, 0, 0); } int main() { ios_base::sync_with_stdio(0); cin >> l >> r; cout << findCount(r) - findCount(l-1) << endl; 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 | /* Rozwiazanie na podstawie artykulu i kodu stad: https://www.geeksforgeeks.org/number-of-integers-in-a-range-l-r-which-are-divisible-by-exactly-k-of-its-digits/ */ #include <bits/stdc++.h> using namespace std; typedef long long int LL; const int LCM = 2520; const int MAX_MASK = (1 << 9) + 1; const int MAX_LEN = 19; LL l, r; LL states[MAX_LEN][2][LCM][MAX_MASK]; vector<int> digits; LL dp(const int idx, const int canZero, const int tight, const int rem, const int mask) { LL& res = states[idx][tight][rem][mask]; if(res != -1) { return res; } res = 0; if(idx == digits.size()) { int usedDigsCount = 0, divisibleByDigsCount = 0; for(int d = 1; d < 10; ++d) { if(mask & (1 << (d-1))) { ++usedDigsCount; if(rem % d == 0) { ++divisibleByDigsCount; } } } if(usedDigsCount == divisibleByDigsCount && usedDigsCount > 0) { res = 1; } } else { for(int d = (canZero ? 0 : 1); d < 10; ++d) { if(tight && d > digits[idx]) { continue; } const int newTight = ((tight == 1) ? (d == digits[idx]) : 0); const int newRem = (10*rem + d) % LCM; const int newCanZero = (canZero && (d == 0)); int newMask = mask; if(d != 0) { newMask = (mask | (1 << (d-1))); } res += dp(idx+1, newCanZero, newTight, newRem, newMask); } } return res; } LL findCount(LL x) { digits.clear(); while(x > 0) { digits.push_back(x%10); x /= 10; } reverse(digits.begin(), digits.end()); memset(states, -1, sizeof(states)); return dp(0, 1, 1, 0, 0); } int main() { ios_base::sync_with_stdio(0); cin >> l >> r; cout << findCount(r) - findCount(l-1) << endl; return 0; } |