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yangdanny97yangdanny97
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add negafibonacci encoding
1 parent ab883c0 commit a70e1f7

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+104
-29
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2 files changed

+104
-29
lines changed

‎index.html

+40-7
Original file line numberDiff line numberDiff line change
@@ -1,23 +1,56 @@
11
<!DOCTYPE html>
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<meta charset="utf-8">
3-
3+
<style>
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input {
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margin-top: 5px;
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}
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</style>
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<body>
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<div>
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<h1>Online Fibonacci Coding Converter</h1>
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<p>
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A simple online tool for converting between decimal numbers and their <a
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href="https://en.wikipedia.org/wiki/Fibonacci_coding">Fibonacci coding</a>.
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A simple online tool for converting between decimal numbers, <a
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href="https://en.wikipedia.org/wiki/Fibonacci_coding">Fibonacci coding</a>, and <a
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href="https://en.wikipedia.org/wiki/Negafibonacci_coding">Negafibonacci coding</a>.
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</p>
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<div>
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<fieldset>
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<legend>From</legend>
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<div><input type="radio" id="fibonacci" name="from" value="fibonacci">
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<label for="fibonacci">fibonacci</label>
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</div>
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<div><input type="radio" id="negafibonacci" name="from" value="negafibonacci">
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<label for="negafibonacci">negafibonacci</label>
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</div>
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<div>
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<input type="radio" id="decimal" name="from" value="decimal" checked>
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<label for="decimal">decimal</label>
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</div>
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</fieldset>
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<fieldset>
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<legend>To</legend>
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<div><input type="radio" id="fibonacci-to" name="to" value="fibonacci" checked>
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<label for="fibonacci">fibonacci</label>
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</div>
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<div><input type="radio" id="negafibonacci-to" name="to" value="negafibonacci">
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<label for="negafibonacci">negafibonacci</label>
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</div>
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<div>
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<input type="radio" id="decimal-to" name="to" value="decimal">
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<label for="decimal">decimal</label>
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</div>
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</fieldset>
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</div>
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<br>
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<div>
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Input:
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<input type="text" id="input" size="50">
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<button id="d2f">Decimal to Fibonacci</button>
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<button id="f2d">Fibonacci to Decimal</button>
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<label for="input">Input</label>
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<button id="convert">Convert</button>
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</div>
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<br>
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<div>
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Output:
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<input type="text" id="output" size="50">
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<label for="output">Output</label>
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</div>
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</div>
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<script src="./script.js"></script>

‎script.js

+64-22
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
const d2f = num => {
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const d2f = (num, neg) => {
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const helper = (f1, f2, n) => {
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if (f2 > n) {
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return [n, "1"];
@@ -10,46 +10,88 @@ const d2f = num => {
1010
return [rem, "0" + b];
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}
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}
13-
if (num <= 0) {
14-
return "Number must be greater than 0";
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const negHelper = (f1, f2, sum, n) => {
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if (Math.abs(sum) > Math.abs(n)) {
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return [n, "1"];
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}
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if ((n < 0 && f1 < 0) || (n > 0 && f1 > 0)) {
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sum += f1;
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}
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[rem, b] = negHelper(f2, f1 + -f2, sum, n);
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const canBe1 = b.charAt(0) !== '1' || b.length === 1;
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if (Math.abs(rem - f1) < Math.abs(rem) && canBe1) {
24+
return [rem - f1, "1" + b];
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} else {
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return [rem, "0" + b];
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}
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}
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30+
if (neg) {
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if (num === 0) {
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return "Number cannot be 0";
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}
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return negHelper(1, -1, 0, num)[1];
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} else {
36+
if (num <= 0) {
37+
return "Number must be greater than 0";
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}
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return helper(1, 1, num)[1];
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}
16-
return helper(1, 1, num)[1];
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};
1842

19-
const f2d = b => {
43+
const f2d = (enc, neg) => {
44+
const n = neg ? -1 : 1;
2045
const helper = (f1, f2, i) => {
21-
if (i >= b.length - 1) {
46+
if (i >= enc.length - 1) {
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return 0;
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}
24-
const char = b.charAt(i);
49+
const char = enc.charAt(i);
2550
if (char == '1') {
26-
return f2 + helper(f2, f1 + f2, i + 1);
51+
return (neg ? f1 : f2) + helper(f2, f1 + n * f2, i + 1);
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} else if (char == '0') {
28-
return helper(f2, f1 + f2, i + 1);
53+
return helper(f2, f1 + n * f2, i + 1);
2954
}
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}
31-
for (var i = 0; i < b.length; i++) {
32-
switch (b.charAt(i)) {
56+
for (var i = 0; i < enc.length; i++) {
57+
switch (enc.charAt(i)) {
3358
case '1':
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case '0':
3560
break;
3661
default:
37-
return `Invalid character at position ${i}: ${b.charAt(i)}`;
62+
return `Invalid character at position ${i}: ${enc.charAt(i)}`;
3863
}
3964
}
40-
if (b.length < 2 || b.charAt(b.length - 1) != '1' || b.charAt(b.length - 2) != '1') {
65+
if (enc.length < 2 || enc.charAt(enc.length - 1) != '1' || enc.charAt(enc.length - 2) != '1') {
4166
return "Last two bits must be 1";
4267
}
43-
return helper(1, 1, 0);
68+
return helper(1, n * 1, 0);
4469
};
4570

46-
document.getElementById("d2f").addEventListener("click", () => {
47-
const input = document.getElementById("input").value;
48-
const output = d2f(parseInt(input));
49-
document.getElementById("output").value = output;
50-
});
51-
document.getElementById("f2d").addEventListener("click", () => {
52-
const input = document.getElementById("input").value;
53-
const output = f2d(input);
71+
document.getElementById("convert").addEventListener("click", () => {
72+
const inputEncoding = document.querySelector('input[name="from"]:checked').value;
73+
const outputEncoding = document.querySelector('input[name="to"]:checked').value;
74+
75+
const input = document.getElementById("input").value.trim();
76+
var output;
77+
if (inputEncoding === outputEncoding) {
78+
output = input;
79+
} else if (inputEncoding === "fibonacci") {
80+
const decimal = f2d(input, false);
81+
if (outputEncoding === "decimal") {
82+
output = decimal;
83+
} else {
84+
output = (/^\d+$/.test(decimal)) ? d2f(decimal, true) : decimal;
85+
}
86+
} else if (inputEncoding === "decimal") {
87+
output = d2f(input, outputEncoding === "negafibonacci");
88+
} else if (inputEncoding === "negafibonacci") {
89+
const decimal = f2d(input, true);
90+
if (outputEncoding === "decimal") {
91+
output = decimal
92+
} else {
93+
output = (/^\d+$/.test(decimal)) ? d2f(decimal, false) : decimal;
94+
}
95+
}
5496
document.getElementById("output").value = output.toString();
5597
});

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