 # HackerRank — Diagonal Difference [easy] — Javascript

Given a square matrix, calculate the absolute difference between the sums of its diagonals.

For example, the square matrix is shown below:

`1 2 34 5 69 8 9`

The left-to-right diagonal = 1+5+9=15 . The right to left diagonal = 3+5+9=17. Their absolute difference is |15–17|=2.

`function diagonalDifference(arr) {    let idx = arr.length - 1    let rightTotal = 0    let leftTotal = 0    for (let i = 0; i < arr.length; i++) {        rightTotal += arr[i][i]        leftTotal += arr[i][idx]        idx--    }    return Math.abs(rightTotal - leftTotal)}`

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# HackerRank — Time Conversion Solution — Javascript

Given a time in -hour AM/PM format, convert it to military (24-hour) time.

Note: — 12:00:00AM on a 12-hour clock is 00:00:00 on a 24-hour clock.
- 12:00:00PM on a 12-hour clock is 12:00:00 on a 24-hour clock.

Example

• s = ‘12:01:00PM.
• Return ‘12:01:00’.
• s = ‘12:01:00AM’.
• Return ‘00:01:00’.
`function timeConversion(s) {    let day = s.slice(8) // pm or am    let time = s.slice(0, 2) // 12    let middle = s.slice(2, -2)if(day === 'PM'){        if(time === '12'){            return `\${time}\${middle}`        } else {            time = Number(time)            let newTime = time += 12            return `\${newTime}\${middle}`        }    } else {        if(time === '12'){            return `00\${middle}`        } else {            return `\${time}\${middle}`        }    }}`

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