Строки

#include <stdio.h>
#include <Windows.h>
#include <iostream>
using namespace std;
int strlen1(char *s) {
    int n = 0;
    while (s[n] != '\0')
        n++;
    return n;
}
int strlen2(char *s) {
    int n;
    for (n = 0; *s; ++s)
        n++;
    return n;
}
int strlen3(char *s) {
    int n = 0;
    for (int i = 0;; i++) {
        if (s[i] != '\0')
            n++;
        else break;
    }
    return n;
}
int strlen4(char *s) {
    int n = 0;
    char *s1 = s;
    begin:
        if (*s1) {
            n++;
            *s1++;
            goto begin;
        }
    return n;
}

char* strcpy1(char *dest, char *s, int p, int k) {
    int N = strlen1(s);
    if (k < 1 || p > N)
        return dest;
    if (p + k > N)
        k = N - p;
    for (int i = 0; i < k; i++, p++) {
        dest[i] = s[p];
    }
    return dest;
}
char* strcpy2(char *dest, char *s, int p, int k) {
    int N = strlen1(s);
    if (k < 1 || p > N)
        return dest;
    if (p + k > N)
        k = N - p;
    int i = 0;
    p++;
    while (k != 0 && dest != '\0') {
        *(dest + i) = *(s + p - 1);
        i++;
        p++;
        k--;
    }
    return dest;
}
char* strcpy3(char *dest, char *s, int p, int k) {
    int N = strlen1(s);
    if (k < 1 || p > N)
        return dest;
    if (p + k > N)
        k = N - p;
    int j = 0;
    while (p <= N && k != 0) {
        dest[j] = s[p];
        p++;
        k--;
        j++;
    }
    return dest;
}
char* strcpy4(char *dest, char *s, int p, int k) {
    int N = strlen1(s);
    if (k < 1 || p > N)
        return dest;
    if (p + k > N)
        k = N - p;
    for (int i = 0; s[i] != 0; i++) {
        if (i < k) {
            dest[i] = s[p];
            p++;
        }
    }
    return dest;
}

int strcmp1(char *s1, char *s2) {
    for (int i = 0; i < strlen1(s1); i++) {
        if (s1[i] < s2[i])
            return -1;
        if (s1[i] > s2[i])
            return 1;
    }
    if (strlen1(s2) > strlen1(s1)) {
        return -1;
    }
    else {
        return 0;
    }
}
int strcmp2(char *s1, char *s2) {
    int i = 0;
    while (s1[i] || s2[i]) {
        if (s1[i] < s2[i])
            return -1;
        if (s1[i] > s2[i])
            return 1;
        i++;
    }
    return 0;
}
int strcmp3(char *s1, char *s2) {
    while (*s1 && *s2) {
        if (*s1 < *s2)
            return -1;
        if (*s1 > *s2)
            return 1;
        *s1++; *s2++;
    }
    if (strlen1(s2) == strlen1(s1)) {
        return 0;
    }
    else {
        if (strlen1(s2) > strlen1(s1)) {
            return -1;
        }
        else
            return 1;
    }
}
int strcmp4(char *s1, char *s2) {
    int N = strlen1(s1);
    int i = 0;
    begin:
    if (i < N) {
        if (s1[i] < s2[i])
            return -1;
        if (s1[i] > s2[i])
            return 1;
        i++;
        goto begin;
    }
    return s2[i] ? -1 : 0;
}

char* strcat1(char *dest, char *s) {
    char *n = dest;
    while (*dest)
        dest++;
    while (*dest++ = *s++)
        ;
    *dest = '\0';
    return n;
}
char *strcat2(char *dest, char *s) {
    int i = 0;
    while (dest[i])
        i++;
    for (int j = 0; j < strlen1(s); j++) {
        dest[i] = s[j];
        i++;
    }
    dest[i] = '\0';
    return dest;
}
char *strcat3(char *dest, char *s) {
    int i = strlen1(dest), j = 0;
    begin:
    if (j < strlen1(s)) {
        dest[i] = s[j];
        i++;
        j++;
        goto begin;
    }
    dest[i] = '\0';
    return dest;
}
char *strcat4(char *dest, char *s) {
    int i, j;
    int N = 0;
    for (i = 0; dest[i]; i++)
        N++;
    for (i = 0; s[i]; i++)
        N++;
    char* n = new char[N + 1];
    for (i = 0, j = 0; dest[i]; i++, j++)
        n[j] = dest[i];
    for (i = 0; s[i]; i++, j++)
        n[j] = s[i];
    n[j] = '\0';
    return n;
}

char* strins1(char *sub, char *s, int p) {
    int N = strlen1(sub) + strlen1(s);
    if (p > strlen1(s))
        p = strlen1(s);
    if (p < 0)
        p = 0;
    char* n = new char[N + 1];
    int i;
    for(i = 0; i <= p - 1; i++)
        n[i] = s[i];
    for (int j = 0; j < strlen1(sub); j++, i++)
        n[i] = sub[j];
    for (int k = p; k < strlen1(s); k++, i++)
        n[i] = s[k];
    n[i] = '\0';
    return n;
}
char* strins2(char *sub, char *s, int p) {
    int N = strlen1(sub) + strlen1(s);
    if (p > strlen1(s))
        p = strlen1(s);
    if (p < 0)
        p = 0;
    char* n = new char[N + 1];
    int j = 0;
    while (s[j] != 0) {
        n[j] = s[j];
        j++;
    }
    n[j] = '\0';
    int i = p, k = 0;
begin1:
    int m = strlen1(n);
begin2:
    n[m + 1] = n[m];
    m--;
    if (m >= i)
        goto begin2;
    n[i] = sub[k];
    i++, k++;
    if (i < strlen1(sub) + p)
        goto begin1;
    return n;
}
char* strins3(char *sub, char *s, int p) {
    int N = strlen1(sub) + strlen1(s);
    if (p > strlen1(s))
        p = strlen1(s);
    if (p < 0)
        p = 0;
    char* n = new char[N + 1];
    int i = 0, k = 0, t = p;
    while (i <= p - 1) {
        n[i] = s[i];
        i++;
    }
    while (k < strlen1(sub)) {
        n[i] = sub[k];
        k++; i++;
    }
    while(t < strlen1(s)) {
        n[i] = s[t];
        t++; i++;
    }
    n[i] = '\0';
    return n;
}
char* strins4(char *sub, char *s, int p) {
    int N = strlen1(sub) + strlen1(s);
    if (p > strlen1(s))
        p = strlen1(s);
    if (p < 0)
        p = 0;
    char* n = new char[N + 1];
    int j = 0;
    while (s[j] != 0) {
        n[j] = s[j];
        j++;
    }
    n[j] = '\0';
    for (int i = p, k = 0; i < strlen1(sub) + p; i++, k++) {
        for (int m = strlen1(n); m >= i; m--)
            *(n + m + 1) = *(n + m);
        *(n + i) = *(sub + k);
    }
    return n;
}
char* strdel1(char *s, int p, int k) {
    if (p + k > strlen1(s))
        k = strlen1(s) - p;
    int i, j;
    for (i = p; i < p + k; i++)
        s[i] = s[i + k];
    for (j = i; j <= strlen1(s) - k; j++)
        s[j] = s[j + k];
    return s;
}
char* strdel2(char *s, int p, int k) {
    if (p + k > strlen1(s))
        k = strlen1(s) - p;
    int i = p;
    while (i <= strlen1(s) - k) {
        s[i] = s[i + k];
        i++;
    }
    return s;
}
char* strdel3(char *s, int p, int k) {
    if (p + k > strlen1(s))
        k = strlen1(s) - p;
    for (int i = p; i <= strlen1(s) - k; i++) {
        *(s + i) = *(s + i + k);
   }
    return s;
}
char* strdel4(char *s, int p, int k) {
    if (p + k > strlen1(s))
        k = strlen1(s) - p;
    begin:
    if (p <= strlen1(s) - k) {
        s[p] = s[p + k];
        p++;
        goto begin;
    }
    return s;
}
void teststrlen(char*s) {
    printf("strlen1('%s')= %d\n", s, strlen1(s));
    printf("strlen2('%s')= %d\n", s, strlen2(s));
    printf("strlen3('%s')= %d\n", s, strlen3(s));
    printf("strlen4('%s')= %d\n", s, strlen4(s));
    printf("\n");
}
void teststrcpy(char *dest, char *s, int p, int k) {
    printf("strcpy1('%s','%s', %d, %d)= ", dest, s, p, k);
    printf("'%s'\n", strcpy1(dest, s, p, k));
    for (int i = strlen1(dest) - 1; i >= 0; i--)
        dest[i] = 0;
    printf("strcpy2('%s','%s', %d, %d)= ", dest, s, p, k);
    printf("'%s'\n", strcpy2(dest, s, p, k));
    for (int i = strlen1(dest) - 1; i >= 0; i--)
        dest[i] = 0;
    printf("strcpy3('%s','%s', %d, %d)= ", dest, s, p, k);
    printf("'%s'\n", strcpy3(dest, s, p, k));
    for (int i = strlen1(dest) - 1; i >= 0; i--)
        dest[i] = 0;
    printf("strcpy4('%s','%s', %d, %d)= ", dest, s, p, k);
    printf("'%s'\n", strcpy4(dest, s, p, k));
    printf("\n");
}
void teststrcmp(char *s1, char *s2) {
    printf("strcmp1('%s','%s')= %d\n", s1, s2, strcmp1(s1, s2));
    printf("strcmp2('%s','%s')= %d\n", s1, s2, strcmp2(s1, s2));
    printf("strcmp3('%s','%s')= %d\n", s1, s2, strcmp3(s1, s2));
    printf("strcmp4('%s','%s')= %d\n", s1, s2, strcmp4(s1, s2));
    printf("\n");
}
void teststrcat(char *dest, char *s) {
    int n = strlen1(dest);
    printf("strcat1('%s','%s')= ", dest, s);
    printf("'%s'\n", strcat1(dest, s));
    for (int i = n + strlen1(s); i >= n; i--)
        dest[i] = 0;
    printf("strcat2('%s','%s')= ", dest, s);
    printf("'%s'\n", strcat2(dest, s));
    for (int i = n + strlen1(s); i >= n; i--)
        dest[i] = 0;
    printf("strcat3('%s','%s')= ", dest, s);
    printf("'%s'\n", strcat3(dest, s));
    for (int i = n + strlen1(s); i >= n; i--)
        dest[i] = 0;
    printf("strcat4('%s','%s')= ", dest, s);
    printf("'%s'\n", strcat4(dest, s));
    for (int i = n + strlen1(s); i >= n; i--)
        dest[i] = 0;
    printf("\n");
}
void teststrins(char *sub, char *s, int p) {
    printf("strins1('%s','%s', %d)= ", sub, s, p);
    printf("'%s'\n", strins1(sub, s, p));
    printf("strins2('%s','%s', %d)= ", sub, s, p);
    printf("'%s'\n", strins2(sub, s, p));
    printf("strins3('%s','%s', %d)= ", sub, s, p);
    printf("'%s'\n", strins3(sub, s, p));
    printf("strins4('%s','%s', %d)= ", sub, s, p);
    printf("'%s'\n", strins4(sub, s, p));
    printf("\n");
}
void teststrdel(char *s, int p, int k) {
    char s1[100]{ 0 }; int i = 0;
    while (s[i]) {
        s1[i] = s[i];
        i++;
    }
    i = 0;
    printf("strdel1('%s', %d, %d)= ", s1, p, k);
    printf("'%s'\n", strdel1(s1, p, k));
    while (s[i]) {
        s1[i] = s[i];
        i++;
    }
    i = 0;
    printf("strdel2('%s', %d, %d)= ", s1, p, k);
    printf("'%s'\n", strdel2(s1, p, k));
    while (s[i]) {
        s1[i] = s[i];
        i++;
    }
    i = 0;
    printf("strdel3('%s', %d, %d)= ", s1, p, k);
    printf("'%s'\n", strdel3(s1, p, k));
    while (s[i]) {
        s1[i] = s[i];
        i++;
    }
    printf("strdel4('%s', %d, %d)= ", s1, p, k);
    printf("'%s'\n", strdel4(s1, p, k));
    printf("\n");
}
int main()
{
    setlocale(LC_ALL, "");
    int answer;
    begin:
    system("cls");
    printf("Выберите функцию:\n1.strlen\n2.strcpy\n3.strcmp\n4.strcat\n5.strins\n6.strdel\n");
    scanf_s("%d", &answer);
    switch (answer) {
    case 1: {
        system("cls");
        printf("Тесты для функции strlen:\n");
        char s1[] = "hello";
        teststrlen(s1);
        char s2[] = "456";
        teststrlen(s2);
        char s3[] = "";
        teststrlen(s3);
        char s4[] = "World123";
        teststrlen(s4);
        system("pause");
        goto begin;
    }
    case 2: {
        system("cls");
        printf("Тесты для функции strcpy:\n");
        int p, k;
        char s1[] = "Hello";
        char dest1[50] = "";
        p = 1;
        k = 3;
        teststrcpy(dest1, s1, p, k);
        char s2[] = "123456";
        char dest2[50] = "";
        p = 3;
        k = 1;
        teststrcpy(dest2, s2, p, k);
        char s3[] = "rabbit";
        char dest3[50] = "";
        p = 10;
        k = 4;
        teststrcpy(dest3, s3, p, k);
        char s4[] = "x123cut97";
        char dest4[50] = "";
        p = 2;
        k = 5;
        teststrcpy(dest4, s4, p, k);
        system("pause");
        goto begin;
    }
    case 3: {
        system("cls");
        printf("Тесты для функции strcmp:\n");
        char s1[] = "Abc", s2[] = "Abc";
        teststrcmp(s1, s2);
        char s3[] = "help", s4[] = "help1";
        teststrcmp(s3, s4);
        char s5[] = "mother", s6[] = "mothEr";
        teststrcmp(s5, s6);
        char s7[] = "01234", s8[] = "01334";
        teststrcmp(s7, s8);
        system("pause");
        goto begin;
    }
    case 4: {
        system("cls");
        printf("Тесты для функции strcat:\n");
        char dest1[50] = "Hello ";
        char s1[] = "world";
        teststrcat(dest1, s1);
        char dest2[50] = "123";
        char s2[] = "456";
        teststrcat(dest2, s2);
        char dest3[50] = "Str";
        char s3[] = "cat";
        teststrcat(dest3, s3);
        char dest4[50] = "100 - 23 = ";
        char s4[] = "77";
        teststrcat(dest4, s4);
        system("pause");
        goto begin;
    }
    case 5: {
        system("cls");
        printf("Тесты для функции strins:\n");
        int p;
        char s1[] = "012345-6";
        char sub[] = "abc";
        p = 6;
        teststrins(sub, s1, p);
        char s2[] = "0123456";
        p = 0;
        teststrins(sub, s2, p);
        char s3[] = "0123456";
        p = 4;
        teststrins(sub, s3, p);
        char s4[] = "0123456";
        p = 12;
        teststrins(sub, s4, p);
        system("pause");
        goto begin;
    }
    case 6: {
        system("cls");
        printf("Тесты для функции strdel:\n");
        int p, k;
        char s1[] = "0123456";
        p = 1;
        k = 2;
        teststrdel(s1, p, k);
        char s2[] = "Машина";
        p = 0;
        k = 2;
        teststrdel(s2, p, k);
        char s3[] = "str-1234del";
        p = 3;
        k = 5;
        teststrdel(s3, p, k);
        char s4[] = "workout478";
        p = 4;
        k = 15;
        teststrdel(s4, p, k);
        system("pause");
        goto begin;
    }
    }
    system("pause");
}