I am new to C and trying to learn shell sorting.I am trying to sort an integer array in ascending order.Here is my code-
#include <stdio.h>
main()
{
int a[] = {1, 9, 7, 4, 8, 6, 7,2,1,6 };
int n =10; //array length
for (int c = (n / 2); c > 0; c = c / 2)
{
for (int i = c; c < n; i++)
{
int t = a[i];
int j;
for (j = i;( j >= c) && (t < a[j - c]); j = j - c)
{
a[j] = a[j - 1];
}
a[j] = t;
}
}
for (int i = 0; i <= 9; i++)
{
printf("%d ", a[i]);
}
}
On compiling this code in Visual Studio Express an error message comes asking either to close or debug and the output terminal not shows any output.I can't figure out what is wrong in this code.I would appreciate if someone could explain, and perhaps point me to a solution that would do what I want.
Your code is almost right, just replace for (int i = c; c < n; i++) with for (int i = c; i < n; i++)
'c' will always be lesser than 'n' that's why your code is falling into infinite loop.
try to add this code....
#include<stdio.h>
#include<conio.h>
int main()
{
int arr[30];
int i,j,k,tmp,num;
printf("Enter total no. of elements : ");
scanf("%d", &num);
for(k=0; k<num; k++)
{
printf("\nEnter %d number : ",k+1);
scanf("%d",&arr[k]);
}
for(i=num/2; i>0; i=i/2)
{
for(j=i; j<num; j++)
{
for(k=j-i; k>=0; k=k-i)
{
if(arr[k+i]>=arr[k])
break;
else
{
tmp=arr[k];
arr[k]=arr[k+i];
arr[k+i]=tmp;
}
}
}
}
printf("\t**** Shell Sorting ****\n");
for(k=0; k<num; k++)
printf("%d\t",arr[k]);
getch();
return 0;
}
Related
I want to randomize a to p without repetition.
int main(){
int array2[4][4];
bool arr[100]={0};
int i;
int j;
srand(time(NULL));
for(i=0; i<=3; i++){
for(j=0; j<=3; j++){
int randomNumber1;
randomNumber1 = (rand() % (82-65+1))+65;
if (!arr[randomNumber1])
{
printf("%c ",randomNumber1);
array2[i][j]=randomNumber1;
}
else
{
i--;
j--;
arr[randomNumber1]=1;
}
}
printf("\n");
}
return;
the output still has repeat alphabet. I want to have the output in 4x4 with with all a to p without it repeating.
There are some errors in your code. IMHO the most serious is that arr[randomNumber1]=1; is is the wrong branch of the test. That means that your current code does not invalidate once a number was used but only if it has already been invalidated => if you control the arr array at the end of the program all value are still 0.
That is not all. When you get a duplicate, you should only reset the inner loop, and you are currently off by 2 in your maximum ascii code: you go up to R when you want to stop at P.
Your code should be:
for (i = 0; i <= 3; i++) {
for (j = 0; j <= 3; j++) {
int randomNumber1;
randomNumber1 = (rand() % (81 - 65)) + 65;
if (!arr[randomNumber1])
{
printf("%c ", randomNumber1);
array2[i][j] = randomNumber1;
arr[randomNumber1] = 1;
}
else
{
//i--;
j--;
}
}
printf("\n");
}
But this kind of code is terribly inefficient. In my tests it took 30 to 60 steps to fill 16 values, because random can return duplicates. This is the reason why you were advised in comments to use instead the modern algorithm for Fisher-Yates shuffle:
int main() {
int array2[16];
unsigned i, j, k=0;
// initialize array with alphabets from A to P
for (i = 0; i < sizeof(array2); i++) {
array2[i] = 'A' + i;
}
// Use Fisher-Yates shuffle on the array
srand(time(NULL));
for (i = 15; i > 0; i--) {
j = rand() % (i + 1);
if (j != i) {
int c = array2[i];
array2[i] = array2[j];
array2[j] = c;
}
}
// Display a 4x4 pattern
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
printf("%c ", array2[k++]);
}
printf("\n");
}
return 0;
}
Which shuffles the array in only 16 steps.
Here is the outline
// Need some #includes here - exercise for the reader
char items[] = "abcdefghijklmnopqrstuvwxyz";
int len = sizeof(items);
srand(time(NULL));
while (len > 0) {
int r = rand() % len;
printf("%c", items[r]);
len--;
items[r] = items[len];
}
This should do the trick to print the whole alphabet in random order without repeats. Modify to do what you need it to do
I've got this problem where I can only compile using the gcc -std=c99 but however, i need it to compile using c89 aka gcc -Wall. This is part of my code where i use the 'for' loop. Please see if you can help me out thank you in advance.
#include<stdio.h>
int main()
{
int arr[100],i=0,ch;
int n = 1, sum = 0;
printf("Check out our selection! \n");
printf("Airhead - 25 cents\n");
printf("Fun Dip - 40 cents\n");
printf("Gummi Bears - 20 cents\n");
while (n != 0)
{
printf("Insert Coins: ");
scanf("%d",&n);
arr[i++] = n;
}
for(int j=0;j<i;j++)
{ sum = sum + arr[j];
}
......
This is wrong:
for (int j = 0; j < i; j++) {
sum = sum + arr[j];
}
You have to initialize j in beginning of function.
int main() {
int j;
...
for (j = 0; j < i; j++) {
sum = sum + arr[j];
}
}
I want to print this pattern like right angled triangle
0
909
89098
7890987
678909876
56789098765
4567890987654
345678909876543
23456789098765432
1234567890987654321
I wrote the following code:
#include <stdio.h>
#include <conio.h>
void main()
{
clrscr();
int i,j,x,z,k,f=1;
for ( i=10;i>=1;i--,f++)
{
for(j=1;j<=f;j++,k--)
{
k=i;
if(k!=10)
{
printf("%d",k);
}
if(k==10)
{
printf("0");
}
}
for(x=1;x<f;x++,z--)
{
z=9;
printf("%d",z);
}
printf("%d/n");
}
getch();
}
What is wrong with this code? When I check manually it seems correct but when compiled gives different pattern
Fairly simple: use two loops, one for counting up and one for counting down. Print literal "0" between the two.
#include <stdio.h>
int main()
{
for (int i = 0; i < 10; i++) {
for (int j = 10 - i; j < 10; j++)
printf("%d", j);
printf("0");
for (int j = 9; j >= 10 - i; j--)
printf("%d", j);
printf("\n");
}
return 0;
}
Like H2CO3's, but since we're only printing single digits why not use putchar():
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
int i, j;
for(i = 0; i < 10; ++i)
{
// Left half.
for(j = 0; j < i; ++j)
putchar('9' - i + j + 1);
// Center zero.
putchar('0');
// Right half.
for(j = 0; j < i; ++j)
putchar('9' - i + j + 1);
putchar('\n');
}
return EXIT_SUCCESS;
}
Modified Code:
Check your errors:
# include<stdio.h>
# include<conio.h>
int main()
{
// clrscr();
int i,j,x,z,k,f=1;
for ( i=10;i>=1;i--,f++)
{
k=i; // K=i should be outside of loop.
for(j=1;j<=f;j++,k++)
{
if(k!=10)
{
printf("%d",k);
}
if(k==10)
{
printf("0");
}
}
z=9; //z=9 should be outside loop.
for(x=1;x<f;x++,z--)
{
printf("%d",z);
}
printf("\n");
}
//getch();
return 0;
}
You are defining k=i inside the for loop(loop which has j) so every time k gets value of i and thus it always get value of i and prints that value and your another condition(if(k==10)) will never be true because every time k takes value of i and i is less than 10 after first iteration of loop and z=9 inside loop so every time loop is executed it is taking value z=9 so it is printing wrong value.
Here's a C# version:
static void DrawNumberTriangle()
{
for (int line = 10; line >=1; line--)
{
for (int number = line; number < 10; number++)
{
System.Console.Write(number);
}
System.Console.Write("0");
for (int number = 9; number > line - 1; number--)
{
System.Console.Write(number);
}
System.Console.WriteLine();
}
}
I'd suggest renaming your i,j,x,z,k,f variables to ones that have meaning like the one's I used. This helps making your code easier to follow.
Rather than output the mid 0 using printf, why not print it using the loops itself.
The following short and simple code can be used:
int main()
{
int m = 10, n, p;
while(m >= 1)
{
for(n = m; n <= 10; n++)
printf("%d", n % 10);
for(p = n - 2; p >= m; p--)
printf("%d", p );
printf("\n");
m--;
}
return 1;
}
For high throughput (though of questionable merit in terms of clarity):
#include <stdio.h>
int main() {
char const digits[] = "1234567890";
char const rdigits[] = "9876543210";
for (int i = 0; i < 30; ++i) {
int k = i % 10;
fputs(digits + 9 - k, stdout);
for (int j = 9; j < i; j += 10) fputs(digits, stdout);
for (int j = 9; j < i; j += 10) fputs(rdigits, stdout);
fwrite(rdigits, 1, k, stdout);
fputs("\n", stdout);
}
}
#include <stdio.h>
void print(int i){
if(i == 10){
putchar('0');
return ;
} else {
printf("%d", i);
print(i+1);
printf("%d", i);
}
}
int main(void){
int i;
for(i = 10; i>0; --i){
print(i);
putchar('\n');
}
return 0;
}
I want to print this pattern like right angled triangle
0
909
89098
7890987
678909876
56789098765
4567890987654
345678909876543
23456789098765432
1234567890987654321
I wrote the following code:
#include <stdio.h>
#include <conio.h>
void main()
{
clrscr();
int i,j,x,z,k,f=1;
for ( i=10;i>=1;i--,f++)
{
for(j=1;j<=f;j++,k--)
{
k=i;
if(k!=10)
{
printf("%d",k);
}
if(k==10)
{
printf("0");
}
}
for(x=1;x<f;x++,z--)
{
z=9;
printf("%d",z);
}
printf("%d/n");
}
getch();
}
What is wrong with this code? When I check manually it seems correct but when compiled gives different pattern
Fairly simple: use two loops, one for counting up and one for counting down. Print literal "0" between the two.
#include <stdio.h>
int main()
{
for (int i = 0; i < 10; i++) {
for (int j = 10 - i; j < 10; j++)
printf("%d", j);
printf("0");
for (int j = 9; j >= 10 - i; j--)
printf("%d", j);
printf("\n");
}
return 0;
}
Like H2CO3's, but since we're only printing single digits why not use putchar():
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
int i, j;
for(i = 0; i < 10; ++i)
{
// Left half.
for(j = 0; j < i; ++j)
putchar('9' - i + j + 1);
// Center zero.
putchar('0');
// Right half.
for(j = 0; j < i; ++j)
putchar('9' - i + j + 1);
putchar('\n');
}
return EXIT_SUCCESS;
}
Modified Code:
Check your errors:
# include<stdio.h>
# include<conio.h>
int main()
{
// clrscr();
int i,j,x,z,k,f=1;
for ( i=10;i>=1;i--,f++)
{
k=i; // K=i should be outside of loop.
for(j=1;j<=f;j++,k++)
{
if(k!=10)
{
printf("%d",k);
}
if(k==10)
{
printf("0");
}
}
z=9; //z=9 should be outside loop.
for(x=1;x<f;x++,z--)
{
printf("%d",z);
}
printf("\n");
}
//getch();
return 0;
}
You are defining k=i inside the for loop(loop which has j) so every time k gets value of i and thus it always get value of i and prints that value and your another condition(if(k==10)) will never be true because every time k takes value of i and i is less than 10 after first iteration of loop and z=9 inside loop so every time loop is executed it is taking value z=9 so it is printing wrong value.
Here's a C# version:
static void DrawNumberTriangle()
{
for (int line = 10; line >=1; line--)
{
for (int number = line; number < 10; number++)
{
System.Console.Write(number);
}
System.Console.Write("0");
for (int number = 9; number > line - 1; number--)
{
System.Console.Write(number);
}
System.Console.WriteLine();
}
}
I'd suggest renaming your i,j,x,z,k,f variables to ones that have meaning like the one's I used. This helps making your code easier to follow.
Rather than output the mid 0 using printf, why not print it using the loops itself.
The following short and simple code can be used:
int main()
{
int m = 10, n, p;
while(m >= 1)
{
for(n = m; n <= 10; n++)
printf("%d", n % 10);
for(p = n - 2; p >= m; p--)
printf("%d", p );
printf("\n");
m--;
}
return 1;
}
For high throughput (though of questionable merit in terms of clarity):
#include <stdio.h>
int main() {
char const digits[] = "1234567890";
char const rdigits[] = "9876543210";
for (int i = 0; i < 30; ++i) {
int k = i % 10;
fputs(digits + 9 - k, stdout);
for (int j = 9; j < i; j += 10) fputs(digits, stdout);
for (int j = 9; j < i; j += 10) fputs(rdigits, stdout);
fwrite(rdigits, 1, k, stdout);
fputs("\n", stdout);
}
}
#include <stdio.h>
void print(int i){
if(i == 10){
putchar('0');
return ;
} else {
printf("%d", i);
print(i+1);
printf("%d", i);
}
}
int main(void){
int i;
for(i = 10; i>0; --i){
print(i);
putchar('\n');
}
return 0;
}
I am trying to write a C code that will print a pyramid structure on screen, something like this.
The corresponding code I've written is something like this.
#include <stdio.h>
#include <stdlib.h>
void printArrayFunc(char arr[9][5]) {
int i, j;
printf("=========================================\nprinting the values\n");
for (i = 0; i < 5; i++) {
for (j = 0; j < 9; j++) {
//printf("arr[%d][%d] = %d\n", i,j, arr[i][j]);
if (arr[i][j] == 1)
printf("*");
else
printf(" ");
}
printf("\n");
}
}
int main() {
int i, j;
char arr[9][5] = {
0
};
printf("============================\nfilling the values\n");
for (i = 0; i < 5; i++) {
for (j = 4 - i; j <= 4 + i; j++) {
arr[i][j] = 1;
// printf("arr[%d][%d]= %d\n",i,j,arr[i][j]);
}
//printf("\n");
}
printArrayFunc(arr);
return 0;
}
It is giving an output like
I know I'm doing some silly mistake but at this moment, I'm not able to find what is going wrong. Let me hear your comments on this.
In the function argument:
char arr[9][5]
In the loop:
for (i = 0; i<5; i++) {
for (j = 0; j<9;j++) {
if (arr[i][j] == 1)
You flipped the position of i and j. i should go from 0 to 9, j from 0 to 5.
if (arr[i][j] == 1)
printf("*");
else
printf(" ");
This statement is giving the garbage value in this statement if if condition is true then it print else statement and when else comes true it prints the garbage value.