我先瞅了一眼数据范围，l <= 10, T <= 15,然后凭着我不灵光的数学10! * 15 = 54432000 ≈ 5e7,于是我们就水一发全排列，然后就卡过去了……
1 #include<cstdio> 2 #include<iostream> 3 #include<algorithm> 4 #include<cmath> 5 #include<cstring> 6 #include<cstdlib> 7 #include<vector> 8 #include<queue> 9 #include<stack> 10 #include<cctype> 11 using namespace std; 12 #define enter puts("") 13 #define space putchar(' ') 14 #define Mem(a) memset(a, 0, sizeof(a)) 15 typedef long long ll; 16 typedef double db; 17 const int INF = 0x3f3f3f3f; 18 const db eps = 1e-8; 19 const int maxn = 12; 20 inline ll read() 21 { 22 ll ans = 0; 23 char ch = getchar(), last = ' '; 24 while(!isdigit(ch)) last = ch, ch = getchar(); 25 while(isdigit(ch)) ans = (ans << 3) + (ans << 1) + ch - '0', ch = getchar(); 26 if(last == '-') ans = -ans; 27 return ans; 28 } 29 inline void write(ll x) 30 { 31 if(x < 0) putchar('-'), x = -x; 32 if(x >= 10) write(x / 10); 33 putchar(x % 10 + '0'); 34 } 35 36 char c[maxn]; 37 int a[maxn]; 38 39 int main() 40 { 41 int T = read(); 42 while(T--) 43 { 44 Mem(c); Mem(a); 45 scanf("%s", c); int n = strlen(c); 46 int d = read(), ans = 0; 47 for(int i = 0; i < n; ++i) a[i] = c[i] - '0'; 48 sort(a, a + n); 49 do 50 { 51 ll x = 0; 52 for(int i = 0; i < n; ++i) x = x * 10 + a[i]; 53 if(!(x % d)) ans++; 54 }while(next_permutation(a, a + n)); 55 write(ans); enter; 56 } 57 }