#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
void sortFloatArray(float* arr, int size);
int readFloatsFromFile(float* arr, FILE* file);
int outputFloatsToFile(float* arr, int size, FILE* file);
int main(int argc, char* argv[]){
    char buffer[BUFSIZ + 1];
    float nums[20000];
    FILE *pfile;
    FILE *ofile;

    if(argc > 1){
        pfile = fopen(argv[1], "r");
        ofile = fopen(argv[0], "w");
    }else{
        puts("Input a filename: ");
        gets(buffer);
        pfile = fopen(buffer, "r");
        puts(buffer);
    }
    int size = readFloatsFromFile(nums, pfile);
    if(size == 0){
        puts("FILE NOT FOUND");
        return 0;
    }
    sortFloatArray(&nums[0], size);
    if(ofile == NULL){
        puts("Output File Name: ");
        gets(buffer);
        pfile = fopen(buffer, "w");
    }
    if(!outputFloatsToFile(&nums[0], size, pfile)){
        puts("CANNOT CREATE FILE");
        return 0;
    }

    return 1;
}
int readFloatsFromFile(float* arr, FILE* file){
    int ndx = 0;
    char buffer[BUFSIZ + 1];
    if(file != NULL){
        while(fgets(buffer, sizeof(buffer), file) != NULL){
            if(buffer[0] != '\n'){
                arr[ndx] = atof(buffer);
                ndx++;
            }
        }
    }else{
        puts("FILE NOT FOUND");
        return 0;
    }
    fclose(file);
    return ndx;
}
int outputFloatsToFile(float* arr, int size, FILE* file){
    if(file != NULL){
        int i;
        for(i = 0;i < size; i++){
            fprintf(file, "%f\n", arr[i]);
        }
    }else{
        puts("CANNOT CREATE FILE");
    }
}
void sortFloatArray(float* arr, int size){
    int i;
    int j = 0;
    for(i = 1; i < size; i++){
        float temp = *(arr+i);
        j = i-1;
        while(j >= 0 && *(arr+j) > temp){
            *(arr+(j + 1)) = *(arr+(j));
            j--;
        }
        *(arr+(j + 1)) = temp;
    }
}