Binomial Coefficient
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| #include<bits/stdc++.h> | |
| using namespace std; | |
| ll nCr(int n, int k) | |
| { | |
| ll ans[n+1][k+1]; | |
| int i,j; | |
| for(int i = 0; i <= n; i++){ | |
| for(int j = 0; j <= min(i,k); j++){ | |
| if(j == 0 || j == i) | |
| ans[i][j] = 1; | |
| else{ | |
| ans[i][j] = ans[i-1][j-1] + ans[i-1][j]; | |
| } | |
| } | |
| } | |
| return ans[n][k]; | |
| } | |
| int bionomialCoeff(int n, int k) | |
| { | |
| int ans[k+1]; | |
| memset(ans, 0, sizeof(ans)); | |
| ans[0] = 1; // nC0 is 1 | |
| for(int i = 1; i <= n; i++){ | |
| // compute next row of pascal triangle using the previous row | |
| for(int j = min(i,k); j > 0; j--) | |
| ans[j] = ans[j] + ans[j-1]; | |
| } | |
| return ans[k]; | |
| } | |
| int main() | |
| { | |
| int n,k; | |
| cin >> n >> k; | |
| cout << bionomialCoeff(n,k)<<endl; | |
| } |
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