Integer roots: Difference between revisions
→header c
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Example: With N=2 and X=2×100<sup>2,000</sup> you would calculate a large integer consisting of the first 2,001 digits (in order) of the square root of two.
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=={{header|C}}==
{{trans|C++}}
<lang C>#include <stdio.h>
#include <math.h>
typedef unsigned long long ulong;
ulong root(ulong base, ulong n) {
ulong n1, n2, n3, c, d, e;
if (base < 2) return base;
if (n == 0) return 1;
n1 = n - 1;
n2 = n;
n3 = n1;
c = 1;
d = (n3 + base) / n2;
e = (n3 * d + base / (ulong)powl(d, n1)) / n2;
while (c != d && c != e) {
c = d;
d = e;
e = (n3*e + base / (ulong)powl(e, n1)) / n2;
}
if (d < e) return d;
return e;
}
int main() {
ulong b = (ulong)2e18;
printf("3rd root of 8 = %lld\n", root(8, 3));
printf("3rd root of 9 = %lld\n", root(9, 3));
printf("2nd root of %lld = %lld\n", b, root(b, 2));
system("pause");
return 0;
}</lang>
{{out}}
<pre>3rd root of 8 = 2
3rd root of 9 = 2
2nd root of 2000000000000000000 = 1414213562</pre>
=={{header|C++}}==
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