Best shuffle: Difference between revisions
Content added Content deleted
m (→{{header|D}}) |
(→{{header|D}}: some improvements) |
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int bestShuffle(in dchar[] s1) { |
int bestShuffle(in dchar[] s1) { |
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int countSamePositions(in dchar[] r1, dchar[] r2, |
int countSamePositions(in dchar[] r1, dchar[] r2, size_t len) { |
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int count; |
int count; |
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for ( |
for (size_t i; i < len; i++) |
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if (r2[i] != '-' && r1[i] == r2[i]) { |
if (r2[i] != '-' && r1[i] == r2[i]) { |
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count++; |
count++; |
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} |
} |
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} |
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return count; |
return count; |
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} |
} |
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const len = s1.length; |
const size_t len = s1.length; |
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auto s2 = s1.dup; |
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if (len < 3) { |
if (len < 3) { |
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s2.reverse; |
s2.reverse; |
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} else { |
} else { |
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auto problemChar = sort!("a[1] > b[1]")(array(group(s2.sort)))[0]; |
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if (problemChar[1] > len / 2) { |
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int j, numToRemove = problemChar[1] - (len - problemChar[1]); |
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foreach (ref c; s2) |
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if (c == problemChar[0]) { |
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c = '-'; |
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if (++j >= numToRemove) break; |
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j++; |
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} |
} |
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} |
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} |
} |
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do { |
do { |
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for ( |
for (size_t i = len; i > 1; i--) |
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swap(s2[i-1], s2[uniform(0, i)]); |
swap(s2[i - 1], s2[uniform(0, i)]); |
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} |
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} while(countSamePositions(s1, s2, len) > 0); |
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} while (countSamePositions(s1, s2, len) > 0); |
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if (s2[i] == '-') { |
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foreach (ref c; s2) |
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if (c == '-') c = problemChar[0]; |
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} |
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} |
} |
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