Google Round B APAC Test

A: The password is composed of n different characters and m length. How many cases are there?

Solution: the equation of state transition is DP [I] [J] = DP [I-1] [J] * j + dp [I-1] [J-1] * (N-J + 1 );

Solution code:

1 // file name:. CPP 2 // Author: darkdream 3 // created time: monday, September 15, 2014, 39 seconds, 4 5 # include <vector> 6 # include <list> 7 # include <map> 8 # include <set> 9 # include <deque> 10 # include <stack> 11 # include <bitset> 12 # include <algorithm> 13 # include <functional> 14 # include <numeric> 15 # include <utility> 16 # include <sstream> 17 # include <iostream> 18 # include <iomanip> 19 # include <cstdio> 20 # include <cmath> 21 # include <cstdlib> 22 # include <cstring> 23 # include <ctime> 24 # define ll long long25 26 using namespace STD; 27 ll DP [200] [200]; 28 # define M 100000000729 int main () {30 freopen ("out", "W", stdout); 31 int T; 32 scanf ("% d", & T); 33 for (int ca = 1; Ca <= T; CA ++) 34 {35 int n, m; 36 scanf ("% d", & N, & M); 37 memset (DP, 0, sizeof (DP )); 38 DP [1] [1] = N; 39 for (INT I = 2; I <= m; I ++) 40 {41 for (Int J = 1; j <= N; j ++) 42 DP [I] [J] = (DP [I-1] [J] * j) % m + dp [I-1] [J-1] * (N-J + 1) % m; 43} 44 printf ("case # % d: % LLD \ n", CA, DP [m] [N] % m); 45} 46 Return 0; 47}

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Google Round B APAC Test