Answer to Question #216939 in C for Mike

Question

Write a program that will randomly generate 1000 uppercase letters. Write those alphabets in a text file

named “in.txt”. Now Sort (in ascending order) all the alphabets in the file “in.txt” using insertion sort. Use

separate function for REPLACEMENT_SORT. Show the sorted output in your console window.

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <time.h>


void REPLACEMENT_SORT(char uppercaseLetters[]){
	int n = 1000;
	int i;
	for(i = 1; i < n; i++) {
		int key = uppercaseLetters[i];
		int j = i - 1;
		//shift until you find the position to place the element 'key'
		while(j >= 0 && uppercaseLetters[j] > key) {
			uppercaseLetters[j+1] = uppercaseLetters[j];
			j--;
		}
		//place element 'key' in the correct position in the sorted part of the array
		uppercaseLetters[j+1] = key;
	}
}


int main() {
	char uppercaseLetters[1000];
	int i;
	FILE *fileSaveAlphabets;
	FILE *fileReadAlphabets;
	fileSaveAlphabets = fopen("in.txt", "w+");
	srand(time(0));
	//Write alphabets in a text file named "in.txt". 
	for (i = 0; i < 1000; i++){
		fprintf(fileSaveAlphabets,"%c",(90 - (rand() % 26)),' ');
	}
	fclose(fileSaveAlphabets);
	//Read uppercase letters from the file
	i=0;
	fileReadAlphabets = fopen("in.txt", "r");
	if(fileReadAlphabets != NULL){
		while(fscanf(fileReadAlphabets, "%c",&uppercaseLetters[i]) != EOF){
			i++;
		}	
	}
	fclose(fileReadAlphabets);
	REPLACEMENT_SORT(uppercaseLetters);
	//Show the sorted output in your console window.
	for (i = 0; i < 1000; i++){
		printf("%c ",uppercaseLetters[i]);
	}
	getchar();
	getchar();
	return 0;
}