string word replace

/*hii This is my logic some of my friend says its to big prog but its easy and please give reply and give some other logic please reply it
Maulin Desai
GNU/GPL :) :) :) */
#include
#include
void main()
{
char s[80],w[80],w1[80];
int i,start,cnt=0,j,k,k1,flag=1,t=0,m,temp,j1,l;
printf("\nEnter string:-\t");
gets(s);
printf("\nEnter Word:-\t");
gets(w);
printf("\nEnter replace word:-\t");
gets(w1);
for(l=0;s[l]!='\0';l++);
for(k=0;w[k]!='\0';k++);
for(k1=0;w1[k1]!='\0';k1++);
for(i=0;s[i]!='\0';i++)
{
if(s[i]!=' ' && s[i+1]!='\0')
{
cnt++;
}
else
{
if(s[i+1]=='\0')
{
cnt++;
i++;
}
temp=cnt;
start=i-cnt;//get the starting pos of particular word
cnt=0;
if(temp!=k)
{
flag=0;
continue;
}
for(j=start;j<=i-1;j++)
{
for(t=0;t {
if(s[j]!=w[t])
{
flag=0;
break;
}
else
{
flag=1;
j++;
}
}
if(flag==1)
{
if(k1!=k)
{
for(t=k;t {
for(m=l;m>=i;m--)
{
s[m+1]=s[m];
}
l++;
}
// printf("\nhello:\t%d",strlen(s));
// puts(s);
t=0;
for(j1=start;j1<=i;j1++)
{
for(;t {
s[j1]=w1[t];
j1++;
}
if(j1 {
s[j1]=' ';
t=k1;
}
}
}
else
{
for(j=start;j {
for(t=0;t {
s[j]=w1[t];
j++;
}
}
}
}
if(flag==1)
break;
}
}
}
printf("\n\n\n\n\t\t\t\tReplace String is Shown Below\n\n\n\n\n\t\t\t\t");
puts(s);
}