//Some utilities ////-->HTML selecting functions<--/// //DOM selecting shorthands const id = id => { return document.getElementById(id); }; const query = query => { return document.querySelector(query); }; ////-->Math functions<--//// //Power of number const power = (n, pow) => { let res = n; if(pow > 0) for(let i = pow; i > 1; i --){ res = res * n; } else if (pow < 0) for(let i = pow; i <= 0; i ++){ res = res / n; } else return 0; return res; }; //Rounding with precision const round = (number,prec = 3) => { n = power(10, prec); x = (number * n); if (x % 1< 0.5) return (x - (x % 1)) / n; else return (x - (x % 1) + 1) / n; }; //Flooring with precision const floor = (input, prec = 3) => { n = power(10, prec); x = (input * n); return (x - (x % 1)) / n; }; //Ceil with precision const ceil = (input, prec = 3) => { n = power(10, prec); x = (input * n); if(x%1>0) return (x - (x % 1) + 1) / n; else return (x - (x % 1)) / n; }; //Square root const sqrt = (x, y = 1) => { let acc = 0.000000000001; if(!x){return 0} if (abs(x / y - y) <= acc){ return y; } else{ return sqrt(x, (x / y + y)/2); } }; //Cube root const cbrt =(x, y = 1) => { let acc = 0.000000000001; if(!x){return 0} if (x < 0){ return -1 * cbrt(abs(x)); } if (abs((x / (y * y)) - y) <= acc){ return y; } else{ return cbrt(x, (y + sqrt(x / y)) / 2); } }; //Scientific notation const scientific = num => { let zero = 0; if (num < 1 && num !== 0) { while (num < 1) { num *= 10; zero -= 1; } } else { while (num > 10){ num /= 10; zero += 1; } } return `${num}*10^${zero}`; }; //Factorial const fact = input => { if(input == 1) return 1; return input * fact(input - 1); }; //Actual program var output, input, output_el, input_el; window.onload=()=>{ input_el=id("input"); output_el=id("output"); }; const check=(input)=>{ if(input===""){ input_el.style.borderColor="red"; output_el.value="Wrong input"; return true; } else{ input_el.style.borderColor="#0F0"; return false; } }; const key=key=>{ if(key==="\n"){ calc(); } }; const calc=()=>{ output_el.textContent = ""; input = input_el.value.replace(/[^\w\+\-\*\/\.\,]/g,"").toLowerCase(); input_el.value = input; if(check(input)){ return; } output = eval(input); if(output > 1000000000 || output < 0.001 && output !== 0){ output = scientific(output); } else{ output = round(output,3); } output_el.innerHTML = `${input} = ${output}`; };

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