C about words reverse [closed] - c

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I tried to use C array to write about the code below.
When I entered=>I am a boy.
The desired output is=>boy a am I.
Here is my code below and it does not work.
I have found the bugs for 2 days and I still could not find the problem
int i,j,k,m,start,temp_end,len;
char str[30];
gets(str);
len=strlen(str);
temp_end=len-1;
for(k=len;k>0;k--)
{
if(str[k]==" ")
start=k;
for(j=start+1;j<temp_end;j++)
{
printf("%c",str[j]);
}
printf(" ");
temp_end=k;
}
for(m=0;m<temp_end;m++)
{
printf("%2c.",str[m]);
}

Answer 1

As others have pointed out there are multiple problems with your code.
In the condition if(str[k]==" "), you are using " " to represent a single space character, which is incorrect. For a single space character you need to use ' '. A " " is a string with a single space character.
You are running the for(j=start+1;j<temp_end;j++) { … } loop every time. However this should be run only when a new space, ' ' is found. You can use a flag for this. Same with printf(" ");, and temp_end = k;
printf("%2c.", str[m]) looks to be like a typo. Why %2c.? You should be doing just "%c".
/* Use a flag to know when to print */
/* 0 means don't print, 1 means print */
int pflag = 0;
for(k = len-1; k >0; k--)
{
if(str[k]==' ') {
pflag = 1; /* new space found, update the flag to print */
start=k;
}
if (pflag == 1) /* check flag to see if print needed */
{
for(j=start+1;j<temp_end;j++)
{
printf("%c",str[j]);
}
printf(" ");
temp_end=k;
pflag = 0; /* reset flag after printing */
}
}
for(m=0;m<temp_end;m++)
{
printf("%c",str[m]);
}
Also, do NOT use gets(). Use fgets() or something else.