#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

int main ( void )
{

        int selection;
        int count = 0;

        char Matrix[50][50] = {' '}; //all elements in this array are a space
        printf("MAIN MENU\n");
        printf("=========\n");
        printf("1.  Input Text\n");
        printf("2.  Encrypt\n");
        printf("3.  Decrypt\n");
        printf("4.  Exit\n");

        while (selection != 4)
        {
/*this
        int i;
        int j;
        for (i= 0; i<50; i++)
                for (j=0; j<50; j++)
                        Matrix[i][j] = ' ';

 not mine*/
        printf("\nSelection:  ");
        scanf("%d", &selection);
//      char tmp[10];
//      gets(tmp);

        printf("\n");

        if (selection == 1)
        {
                char input[50] = {' '};
                char rtn[2] = "\0";
                int x;
                while (getchar() != '\n')
                {}

int i;
        int j;
        for (i= 0; i<50; i++)
                for (j=0; j<50; j++)
                        Matrix[i][j] = ' ';

 not mine*/
        printf("\nSelection:  ");
        scanf("%d", &selection);
//      char tmp[10];
//      gets(tmp);

        printf("\n");

        if (selection == 1)
        {
                char input[50] = {' '};
                char rtn[2] = "\0";
                int x;
                while (getchar() != '\n')
                {}

                        printf("--->  ");
                        gets(input);

                while (strcmp(input, "\0") != 0)
                {
                        int i;
                        for (i = 0; i < 50; i ++)
                                Matrix[count][i] = input[i];
                                //strcpy(Matrix[count][i], input[i]);
                        count ++;
                        printf("--->  ");
                        gets(input);
                }

                int l, m;
                printf("\n");
                for (l = 0; l < 50; l ++)
                        for (m = 0; m < 50; m ++)
                                printf("%c", Matrix[l][m]);
        }

 if (selection == 2)
        {
                int shift, c, e, f;
                printf("Please enter a number:  ");
                scanf("%d", &shift);
                for (c = 0; c < 50; c ++)
                {
                        int d;
                        for (d = 0; d < 50; d ++)
                        {
                                //wrapping function
                                if (Matrix[c][d] < 91 && Matrix[c][d] > 64)
                                {
                                        Matrix[c][d] += shift;
                                        while (Matrix[c][d] > 90)
                                                Matrix[c][d] = (Matrix[c][d] - 90) + 64;
                                }
                                if (Matrix[c][d] < 123 && Matrix[c][d] > 96)
                                {
                                        Matrix[c][d] += shift;
                                        while (Matrix[c][d] > 122)
                                                Matrix[c][d] = (Matrix[c][d] - 122) + 97;
                                }
                        }
                }
                for (e = 0; e < 50; e ++)
                        for (f = 0; f < 50; f ++)
                                printf("%c", Matrix[e][f]);
        }

        if (selection == 3)
        {
         int mshift, g, j, k;
                printf("Please enter a number:  ");
                scanf("%d", &mshift);
                for (g = 0; g < 50; g ++)
                {
                        int h;
                        for (h = 0; h < 50; h ++)
                        {

if (Matrix[g][h] < 91 && Matrix[g][h] > 64)
                                {
                                        Matrix[g][h] -= mshift;
                                        while (Matrix[g][h] < 65)
                                                Matrix[g][h] = 90 - (64 - Matrix[g][h]);
                                }
                                if (Matrix[g][h] < 123 && Matrix[g][h] > 96)
                                {
                                        Matrix[g][h] -= mshift;
                                        while (Matrix[g][h] > 122)
                                                Matrix[g][h] = 122 - (96 - Matrix[g][h]);
                                }
                        }
                }
                for (j = 0; j < 50; j ++)
                        for (k = 0; k < 50; k ++)
                                printf("%c", Matrix[j][k]);
        }

        if (selection == 4)
                break;
        }
}