题意:给求给定区间中该数能整除每一位的数的数量。
析:dp[i][j][k] 表示前 i 位,取模2520为 j,最小倍数是 k,但是这样,数组开不下啊,那怎么办呢,其实,0-9的最小公倍数的不同各类并没有那么多,
其实就48种,所以我们可以给这48个一个编号,然后就能开出来了。
代码如下:
#pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring> #include <set> #include <queue> #include <algorithm> #include <vector> #include <map> #include <cctype> #include <cmath> #include <stack> #define freopenr freopen("in.txt", "r", stdin) #define freopenw freopen("out.txt", "w", stdout) using namespace std; typedef long long LL; typedef pair<int, int> P; const int INF = 0x3f3f3f3f; const double inf = 0x3f3f3f3f3f3f; const LL LNF = 0x3f3f3f3f3f3f; const double PI = acos(-1.0); const double eps = 1e-8; const int maxn = 1e3 + 100; const int mod = 1e9 + 7; const int dr[] = {-1, 0, 1, 0}; const int dc[] = {0, 1, 0, -1}; //const char *Hex[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"}; int n, m; const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; inline int Min(int a, int b){ return a < b ? a : b; } inline int Max(int a, int b){ return a > b ? a : b; } inline LL Min(LL a, LL b){ return a < b ? a : b; } inline LL Max(LL a, LL b){ return a > b ? a : b; } inline int gcd(int a, int b){ return b ? gcd(b, a%b) : a; } inline int lcm(int a, int b){ return a * b / gcd(a, b); } inline bool is_in(int r, int c){ return r >= 0 && r < n && c >= 0 && c < m; } const int all[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 18, 20, 21, 24, 28, 30, 35, 36, 40, 42, 45, 56, 60, 63, 70, 72, 84, 90, 105, 120, 126, 140, 168, 180, 210, 252, 280, 315, 360, 420, 504, 630, 840, 1260, 2520}; LL dp[25][2600][50]; int a[25]; map<int, int> id; map<int, int> mp; void init(){ for(int i = 0; i < 48; ++i) mp[i] = all[i], id[all[i]] = i; } LL dfs(int pos, int val, int num, bool ok){ if(!pos) return !(val % mp[num]); LL &ans = dp[pos][val][num]; if(!ok && ans >= 0) return ans; LL res = 0; int n = ok ? a[pos] : 9; for(int i = 0; i <= n; ++i) if(!i) res += dfs(pos-1, val*10%2520, num, ok && i == n); else res += dfs(pos-1, (val*10+i)%2520, id[lcm(mp[num], i)], ok && i == n); return ok ? res : ans = res; } LL solve(LL n){ int len = 0; while(n){ a[++len] = n % 10; n /= 10; } return dfs(len, 0, 0, true); } int main(){ init(); memset(dp, -1, sizeof dp); int T; cin >> T; LL n, m; while(cin >> m >> n){ cout << solve(n) - solve(m-1) << endl; } return 0; }
CodeForces 55D Beautiful numbers (数位DP)
原文:http://www.cnblogs.com/dwtfukgv/p/5958393.html