21 lines
384 B
C++
21 lines
384 B
C++
/** Starting in the top left corner of a 2*2 grid, there are 6 routes (without backtracking) to the bottom right corner.
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How many routes are there through a 20*20 grid? */
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#include "0.hpp"
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#define _max 20
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int main()
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{
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double pro = 1.0;
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for(int i = 1; i <= _max; i++) {
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pro *= (i + (double)_max);
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pro /= i;
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}
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cout << (long long int)pro << endl;
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return 0;
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}
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