Minimum Deletions to Make Character Frequencies Unique

MinDeletions.ts

type Frequency = { [key: string]: number };

function minDeletions(s: string): number {
    const stringArr: string[] = s.split('');

    // Get the character frequencies
    const freq: Frequency  = {};
    stringArr.map((str) => {
        freq[str] = Number(freq?.[str] || 0) + 1;
    });

    const values = Object.values(freq);

    // highest to lowest
    values.sort((a,b) => b-a)

    // deletions
    let deletions = 0;

    // loop through frequency values
    for (let i=0; i < values.length; i++) {
        // set current value
        let n = values[i];
        
        // look ahead in the array to find duplicate frequencies (n)
        for (let j = i+1; j < values.length; j++) {
            // if look ahead value is non-zero and equal to current number (n)
            // then delete one from look ahead value
            if (values[j] && n === values[j]) {
                values[j]--;
                deletions++;
            }
        }
    }
    
    console.log("Deletions > ", deletions);

    return deletions;
};