1 min read
https://practice.geeksforgeeks.org/problems/painting-the-fence3727/1
class Solution {
long long dp[100005];
public:
long long countWays(int n, int k) {
memset(dp, 0, sizeof(dp));
long long mod = 1000000007;
dp[1] = k;
dp[2] = k * k;
for (int i = 3; i <= n; i++) {
dp[i] = ((k - 1) * (dp[i - 1] + dp[i - 2])) % mod;
}
return dp[n];
}
};