char *Mystrncat(char* arr1, const char* arr2, int n){
char* end = arr1;
assert(arr1);
assert(arr2);
while (*arr1 != '\0'){
arr1++;
}
while (n--){
*arr1 = *arr2;
arr1++;
arr2++;
}
*arr1 = '\0';
return end;
}
char* Mystrncpy(char* arr1, const char* arr2, int n){
assert(arr1);
assert(arr2);
char* p = arr1;
for (int i = 0; i < n; i++){
*arr1 = *arr2;
arr1++;
arr2++;
}
*arr1 = '\0';
return p;
}
int Mystrncmp(const char* str1, const char* str2,int n){
assert(str1 != NULL&&str2 != NULL);
while (*str1 == *str2&&*str1 != '\0'&&*str2 != '\0'&&*str1 == *str2){
str1++;
str2++;
}
return *str1 - *str2;
}