The Snail in the Well ? JS

Question

The snail climbs up 7 feet each day and slips back 2 feet each night.
How many days will it take the snail to get out of a well with the given depth?

Sample Input:
31

Sample Output:
6

Explanation: Let's break down the distance the snail covers each day:
Day 1: 7-2=5
Day 2: 5+7-2=10
Day 3: 10+7-2=15
Day 4: 15+7-2=20
Day 5: 20+7-2=25
Day 6: 25+7=32
So, on Day 6 the snail will reach 32 feet and get out of the well at day, without slipping back that night.

Hint: You can use a loop to calculate the distance the snail covers each day, and break the loop when it reaches the desired distance.

Answer 1

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here

i = 0;

for (; depth > 0;) {
i++;

depth -= 7
if (depth > 0) {
depth += 2
}
}
console.log(i);
}

Here ya go m8.

Answer 2

For those interested, here's an explanation on why Ibrahim Matar's answer works.

function main() {
var depth = parseInt(readLine(), 10);

for(dis = 7, day = 1; dis < depth; dis += 7, day++) {
dis -= 2
}
console.log(day);
}

A key part of understanding this lies in knowing the order in which a for loop is evaluated and executed.

There are four parts of a for loop (I’ll include the corresponding code from the answer in parentheses for clarity):
- initialization (dis = 7, day = 1)
- condition (dis < depth)
- final-expression (dis += 7, day++)
- statement (dis -= 2)

Although they are presented in the order listed above, they actually run in this order:
1. initialization
(“dis” is declared and given a value of 7, “day” is declared and given a value of 1)

2. condition
(if “dis < depth” is true, the for loop will continue onto steps 3 and 4. If it is false, the for loop will stop immediately without executing steps 3 and 4)

3. statement
(“dis” is decreased by 2)

4. final-expression
(“dis is increased by 7, “day” is increased by 1)

From here, the loop will run again, but it starts with step 2 (“dis < depth”), not the first one. This is evaluated, once again looking for either true or false.

Going through it step by step. Let’s say “depth = 11”.

First time through the loop:
- dis is set to 7, day is set to 1
- dis (which is 7) < depth (which is 11) = true (the for loop continues to steps 3 and 4)
- dis (which is 7) is decreased by 2, so dis is now 5
- dis (which is 5) is increased by 7, so dis is now 12; and day (which is 1) is increased by 1, so day is now 2

Second time through the loop:
- dis (which is 12) < depth (which is 11) = false (the for loop does not continue to steps 3 and 4)
- the for loop ends, console.log(day) is executed, and at this moment, day has a value of 2

With more space this could be explained further, but this is why extra conditionals, variables, while loops, and arrays aren't necessary here.

Answer 3

My answer is here.

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here

var climb = 7;
var slip = 2;
var day = 0;
for(workdone=0;workdone<=depth;) {
day = day + 1;
workdone=workdone+climb;
if(workdone>=depth){
break;
}
workdone = workdone - slip;

}
console.log(day);
}

Answer 4

console.log(Math.round(depth / 5))

Answer 5

My noob code
for(x=1; depth >0; x++){
depth -=7;
if(depth<=0){
console.log(x);
break;
}
depth +=2;
if(depth<=0){
console.log(x);
break;
}
}

Answer 6

So I wasted a lot of time with the loop method, I decided to find a way to simplify the problem by exploring other options and this is what I came up with.

function main() {
var depth = parseInt(readLine(), 10);

day = depth/5;
console.log(Math.round(day));
}

We know that the snail moves 7 and slides back 2 each night; so that is 5 per day.

We know depth is determined by user input.

So we divide depth by 5 and we get a number and decimal.

Using the Math.round() function we eliminate our decimal and store the answer in the var day.

Hope this helps.

Answer 7

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here
for (dis=7,day=1;dis<depth;dis+=7,day++){
dis=dis-2;
}
console.log (day)

}

Answer 8

var climb = 7;

var slip = 2;

var day = 0;

for(workdone=0; workdone=depth;) {
day = day + 1;
workdone=workdone + climb;
if(workdone = depth){
break;
}

workdone = workdone - slip;

}

console.log(day);

}

Answer 9

function main() {
var depth = parseInt(readLine(), 10); //equals 42 in this example
var x = 0; //milesDone
var y = 0; //dayCount
for(i=0 ; i < depth ;i ++){
if (x<depth) {
x += 7;
if (depth > x) {
x -= 2;
}
y++

} else {
console.log(y)
break;
}
}
}

Answer 10

-----------------------------------
PASSED ALL TEST CASES
-----------------------------------

// VARIABLES
const climb = 7;
const slip = -2;
let day = 0;

// SOLUTION
for (progress = 0; progress <= depth;) {
progress += climb;
day +=1;
if (progress >= depth) {
break;
}
else {
progress += slip;
}
}

// OUTPUT
console.log(day);

Answer 11

thats my code:

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here
var day = 0;
var way = 0;

while (way < depth) {
way += 7;
day++;

if (way >= depth) {
break;
}
way -= 2;
}

console.log(day);
}

Answer 12

function main() {
var profundidade = parseInt(readLine(), 10);
// seu código vai aqui, rsrs exclusivo pra Br
for (i = 0; profundidade > 0; i++) {
profundidade -= 7
if (profundidade > 0) {
profundidade += 2
}
}
console.log(i);
}

Answer 13

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here

let data = []; /** Array contains the distance snails moves per days
after an incremental +7 and decreamental -2 */

for (let i = 7; depth > 0 && i < depth + 7; i += 7) {

if (i < depth) i -= 2; /**it only subtracts 2 as far my incremental
value of +7 is less than or equal to input value
*/
data.push(i);

};

console.log(data.length); /**this will output the length of data
which will be the number of days */
}

or

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here

for ( i = 7, day = 1; i < depth; i += 7, day++) {

if (i < depth) i -= 2; /**it only subtracts 2 as far my incremental
value of +7 is less than or equal to input value
*/

};

console.log(day);
/**this will output the length of data
which will be the number of days */
}

Answer 14

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here

i = 0;

for (; depth > 0;) {
i++;

depth -= 7
if (depth > 0) {
depth += 2
}
}
console.log(i);
}

Answer 15

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here
var sum = 0;
var i=1;
while (i>0)
{
sum += 7;
if (sum>=depth)
break;
else
sum -= 2;
i++;
}
console.log(i);
}

Answer 16

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here

//distance = distance covered

var distance=0;
var days=1;

while(distance<depth)
{
distance += 7;

if(distance<depth)

{
distance-=2;
days++;
}

}

console.log(days);

}

Answer 17

But why ? Initial 1 day/7 feet not 0 ?

Answer 18

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here
var day=parseInt(0);
var ng=parseInt(2);
var clday=parseInt(7);

for(days=0;days<=depth;){
day=day+1;
days=days+clday;
if(days>=depth){
break;
}

days=days-ng;

}

console.log(day);
}

hooora!!!

Answer 19

function main() {
var depth = parseInt(readLine(), 10);
//your code goes here
if(depth%5<=2)
console.log(parseInt(depth/5));
else
console.log(parseInt(depth/5)+1);
}

Answer 20

climb =0
for(day=1;climb <depth;day++){
if (climb <depth){
climb =climb +7;
if (climb >=depth){
document.write(day);
}
else{
climb =climb -2;
}
}
}