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1.4. Solution with bit array/vector #43

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1.4. Solution with bit array/vector #43

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30 changes: 29 additions & 1 deletion chapter01/1.4 - PalinPerm/palinPerm.js
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Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,34 @@ var palinPerm = function(string) {
return isPerm;
};

const getCharCode = (c, min = 'a'.charCodeAt(), max = 'z'.charCodeAt()) => {
cCharCode = c.charCodeAt();
return min <= cCharCode && cCharCode <= max
? cCharCode - min : -1;
};

const toggleBit = (bitVector, index) => {
if(index < 0) return bitVector;
return bitVector ^ (1 << index);
};

const getBitVector = str => {
let bitVector = 0;
for(let c of str) {
bitVector = toggleBit(bitVector, getCharCode(c));
}
return bitVector;
};

const palinPermBitVector = str => {
const bitVector = getBitVector(str);
return !(bitVector && (bitVector & (bitVector - 1)));
};

// TESTS
console.log(palinPerm('Tact Coa'), 'true');
console.log(palinPerm('Tact boa'), 'false');
console.log(palinPerm('Tact boa'), 'false');
console.log(palinPermBitVector('cviic'), 'true');
console.log(palinPermBitVector('civie'), 'false');
console.log(palinPermBitVector('damma'), 'true');
console.log(palinPermBitVector('aadmn'), 'false');