ParamRadix.m

+ (void)paramRadixSort:(int*)input length:(int)l radix:(int)r {
    int max = [self findMax:input length:l];
    int partiallySorted[l];
    int i;
    
    int sigDig = 1;
    int bin[r];
    while (sigDig < max) {
        for (int i = 0; i < r; i++) bin[i] = 0;
        
        for (i = 0; i < l; i++) bin[(input[i] / sigDig) % r]++; // get counts of current digits
        for (i = 1; i < r; i++) bin[i] += bin [i - 1]; // convert counts to array indices
        
        for (i = l - 1; i >= 0; i--) partiallySorted[--bin[(input[i] / sigDig) % r]] = input[i];
        for (i = 0; i < l; i++) input[i] = partiallySorted[i];
        
        sigDig *= r;
    }
}