48 lines
1.4 KiB
JavaScript
48 lines
1.4 KiB
JavaScript
function main(s, e, bs, pbs) {
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bs = bs || 10;
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pbs = pbs || 10
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document.write('start:', toString(s), ' end:', toString(e),
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' base:', bs, ' printBase:', pbs)
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document.write('<br>castOutNine: ');
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castOutNine()
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document.write('<br>kaprekar: ');
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kaprekar()
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document.write('<br><br>')
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function castOutNine() {
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for (var n = s, k = 0, bsm1 = bs - 1; n <= e; n += 1)
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if (n % bsm1 == (n * n) % bsm1) k += 1,
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document.write(toString(n), ' ')
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document.write('<br>trying ', k, ' numbers instead of ', n = e - s + 1,
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' numbers saves ', (100 - k / n * 100)
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.toFixed(3), '%')
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}
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function kaprekar() {
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for (var n = s; n <= e; n += 1)
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if (isKaprekar(n)) document.write(toString(n), ' ')
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function isKaprekar(n) {
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if (n < 1) return false
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if (n == 1) return true
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var s = (n * n)
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.toString(bs)
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for (var i = 1, e = s.length; i < e; i += 1) {
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var a = parseInt(s.substr(0, i), bs)
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var b = parseInt(s.substr(i), bs)
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if (b && a + b == n) return true
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}
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return false
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}
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}
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function toString(n) {
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return n.toString(pbs)
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.toUpperCase()
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}
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}
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main(1, 10 * 10 - 1)
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main(1, 16 * 16 - 1, 16)
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main(1, 17 * 17 - 1, 17)
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main(parseInt('10', 17), parseInt('gg', 17), 17, 17)
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