Hello, I want to know what is wrong in my program

Question

This program calculate how day take a snail to be out, in day he run 7 feet and at night -2
function main() {
var di = parseInt(readLine(), 10);
var s=0
var f;
var d=0;
do{
d=d+1
f=s+7;
if (f==di){
console.log(d)
break;
}
s=f-2;
}while (s!=di);
if (s==di){console.log(d)}

}

Answer 1

f value can exceed the di . Then there is no stoping loop.
Use >= instead of == , in if condition.
And no need to print d again out side loop.

Answer 2

function main() {
var di = parseInt(readLine(), 10);
var s=0
var f;
var d=0;
do{
d=d+1
f=s+7;
if (f >=di ){
console.log(d)
break;
}
s=f-2;
}while (s!=di);

//if (s==di){console.log(d)}

}

See if you use
if( f==di)
break ;

Then what if example di = 30 but f = 34 , you should break the loop as it reaches depth already. But f==di is not true so it won't stop loop and s!=di (32!=30) is true so it continues loop so never after f==di comes true. Then it is infinite loop.

You must use condition
if( f >= di)
break;
And if you print day value before break then no need to print after loop. Of course if condition is false though. So Never print I think.

Answer 3

Thank you, in the first time I guessing that you talk about the second if sorry
But I don't understand why my first solution is wrong can you explain please because I really need the answer.

Answer 4

It said in output "execution timed out
"

Answer 5

Yes. It is because infinite looping..
Read my reply ☝again for solution.

Answer 6

Thank you very much for help,

Answer 7

Side note: get used to using meaningful variable names. They help a lot in debugging.