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convert.js
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convert.js
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const reconstruct = function(n, mod){
var v = [mod, 0];
var w = [n, 1];
while(w[0]*w[0]*2 > mod){
q = Math.floor(v[0] / w[0]);
z = [v[0] - q*w[0], v[1] - q*w[1]];
v = w;
w = z;
console.log(JSON.stringify(w));
}
if(w[1] < 0){
w[0] *= -1;
w[1] *= -1;
}
return w;
}
const add_rational_expression = function(original, mod){
original += '*';
var buffer = "";
var res = "";
for(var i = 0;i < original.length;i++){
var c = original[i];
if('0' <= c && c <= '9'){
buffer += c;
}
else{
if(buffer != ""){
var num = parseInt(buffer);
if(num < mod && num * num * 2 > mod){
w = reconstruct(num, mod);
buffer += ' <font color="red">' + w[0] + "/" + w[1] + "</font> ";
}
res += buffer;
buffer = "";
}
res += c;
}
}
return res.slice(0, -1);
}
window.onload = function() {
var mod = -1;
var statement = document.getElementById("task-statement");
var src = statement.innerHTML;
if(src.indexOf("998244353") != -1){
mod = 998244353;
}
if(src.indexOf("1000000007") != -1 || src.indexOf("10^{9}+7") != -1){
mod = 1000000007;
}
if(mod != -1){
statement.innerHTML = add_rational_expression(src, mod);
}
};