Prototip cautare in string

#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <iostream>


void main() {
    int n, i = 0, k;
    char a[30];
    char b[30];
    char introducere;
    //printf("text initial:%s\n", a);
    while ((introducere = _getch()) != '\r') {
        a[i] = introducere;
        printf("%c", a[i]);
        if (i < 29)
            i++;
        else break;

    }

    if (introducere == '\r')
        a[i] = '\0';
    introducere = 'a';
    i = 0;
    printf("\n");
    while ((introducere = _getch()) != '\r') {
        k = i;
        b[i] = introducere;
        printf("%c", b[i]);
        if (i < 29)
            i++;
        else break;

    }
    k++;
    if (introducere == '\r')
        b[i] = '\0';
    printf("\n");
    for (i = 0; i < 30; i++) {
        if (a[i]!='\0')
            printf("%c", a[i]);
        else break;

    }
    printf("\n");

    for (i = 0; i < 30; i++) {
        if (b[i]!='\0')
            printf("%c", b[i]);
        else break;
    }

    if (strstr(a, b) != NULL) {
            printf("\ns-a gasit");
    }
    else printf("\nnu s-a gasit");
    //printf("\na[0]=%c", a[0]);
    //printf("\nb[0]=%c", b[0]);

    _getch();
}