lab2.c

#include<stdio.h>
#include<conio.h>
void main()
{
char STR[100],PAT[100],REP[100],ans[100];
int i,j,c,m,k,flag=0;

printf("\nEnter the MAIN string: \n");
gets(STR);
printf("\nEnter a PATTERN string: \n");
gets(PAT);
printf("\nEnter a REPLACE string: \n");
gets(REP);
i = m = c = j = 0;
while ( STR[c] != '\0')
{
// Checking for Match
if ( STR[m] == PAT[i])
{
i++;
m++;
flag=1;
if ( PAT[i] == '\0')
{
//copy replace string in ans string
for(k=0; REP[k] != '\0';k++,j++)
ans[j] = REP[k];
i=0;
c=m;
}

}
else //mismatch
{
ans[j] = STR[c];
j++;
c++;
m = c;
i=0;
}
}
if(flag==0)
{
printf("Pattern doesn't found!!!");
}
else
{
ans[j] = '\0';
printf("\nThe RESULTANT string is:%s\n" ,ans);
}
getch();
}