51 lines
1.9 KiB
JavaScript
51 lines
1.9 KiB
JavaScript
window.onload = function(){
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var list = [];
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var j = 0;
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for(var c = 1; c <= 200; c++)
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for(var b = 1; b <= c; b++)
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for(var a = 1; a <= b; a++)
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if(gcd(gcd(a, b), c) == 1 && isHeron(heronArea(a, b, c)))
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list[j++] = new Array(a, b, c, a + b + c, heronArea(a, b, c));
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sort(list);
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document.write("<h2>Primitive Heronian triangles with sides up to 200: " + list.length + "</h2><h3>First ten when ordered by increasing area, then perimeter:</h3><table><tr><th>Sides</th><th>Perimeter</th><th>Area</th><tr>");
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for(var i = 0; i < 10; i++)
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document.write("<tr><td>" + list[i][0] + " x " + list[i][1] + " x " + list[i][2] + "</td><td>" + list[i][3] + "</td><td>" + list[i][4] + "</td></tr>");
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document.write("</table><h3>Area = 210</h3><table><tr><th>Sides</th><th>Perimeter</th><th>Area</th><tr>");
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for(var i = 0; i < list.length; i++)
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if(list[i][4] == 210)
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document.write("<tr><td>" + list[i][0] + " x " + list[i][1] + " x " + list[i][2] + "</td><td>" + list[i][3] + "</td><td>" + list[i][4] + "</td></tr>");
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function heronArea(a, b, c){
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var s = (a + b + c)/ 2;
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return Math.sqrt(s *(s -a)*(s - b)*(s - c));
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}
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function isHeron(h){
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return h % 1 == 0 && h > 0;
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}
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function gcd(a, b){
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var leftover = 1, dividend = a > b ? a : b, divisor = a > b ? b : a;
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while(leftover != 0){
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leftover = dividend % divisor;
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if(leftover > 0){
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dividend = divisor;
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divisor = leftover;
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}
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}
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return divisor;
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}
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function sort(list){
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var swapped = true;
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var temp = [];
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while(swapped){
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swapped = false;
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for(var i = 1; i < list.length; i++){
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if(list[i][4] < list[i - 1][4] || list[i][4] == list[i - 1][4] && list[i][3] < list[i - 1][3]){
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temp = list[i];
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list[i] = list[i - 1];
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list[i - 1] = temp;
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swapped = true;
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}
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}
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}
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}
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}
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