41 lines
1.0 KiB
C++
41 lines
1.0 KiB
C++
/*
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* C++ Program to Compute Combinations using Factorials
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*/
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#include<iostream>
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using namespace std;
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long long C(int n, int r)
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{
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long long f[n + 1];
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f[0] = 1;
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for (int i = 1; i <= n; i++)
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f[i] = i * f[i - 1];
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return f[n] / f[r] / f[n - r];
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}
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//Main
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int main()
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{
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int n, r, m;
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while (1)
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{
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cout<<"Enter total number of objects:(0 to exit) ";
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cin>>n;
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if (n == 0)
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break;
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cout<<"Enter number of objects to be chosen: ";
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cin>>r;
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cout<<"Number of Combinations: "<<C(n, min(r, n - r))<<endl;
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}
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}
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/*
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Enter total number of objects:(0 to exit) 10
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Enter number of objects to be chosen: 2
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Number of Combinations: 45
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Enter total number of objects:(0 to exit) 5
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Enter number of objects to be chosen: 2
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Number of Combinations: 10
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Enter total number of objects:(0 to exit) 15
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Enter number of objects to be chosen: 7
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Number of Combinations: 6435
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Enter total number of objects:(0 to exit) 0
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