lab13

int mystrlen(char* arr)
{
    int count = 0;
    while (arr[count] != 0)
    {
        count++;
    }
    return count;
}

char* mystrcpy(char* arr, char* arr2)
{
    int count = 0;
    int i = 0;
    while (arr2[count] != 0)
    {
        arr[count] = arr2[count];
        count++;
    }
    arr[count] = 0;
    return arr;
}

char* mystrcat(char* arr, char* arr2)
{
    int i = 0;
    int cnt = 0;
    int lenfirst = mystrlen(arr);
    int lensecond = mystrlen(arr2);
    int obshaya = lenfirst + lensecond;
    while (lenfirst < obshaya)
    {
        arr[lenfirst] = arr2[i];
        i++;
        lenfirst++;
    }
    arr[obshaya] = 0;
    return arr;
}

int mystrcmp(char* arr, char* arr2)
{
    int i = 0;
    int cnt = 0;
    int x;
    int a, b;
    int lenfirst = mystrlen(arr);
    int lensecond = mystrlen(arr2);
    if (lenfirst > lensecond)
        x = lenfirst;
    else
        x = lensecond;
    while (i < x)
    {
        if (arr[i] != arr2[i])
        {
            a = arr[i];
            b = arr2[i];
            cnt = a - b;
        }
        i++;
    }
    return cnt;
}

char* mystrchr(const char* str, int c)
{
    int i = 0;
    while (str[i] != c) ++i;
    if (c == str[i])
        return (char*)str + 1;
    else
        return 0;
}