String processing 2

1. Write a function int fun (char * p) to determine whether a string is a background bool isHuiwen (const char * str );

2 string reverse order: char * inverseString (char * str );

3. Find the character with the highest frequency in the string: char maxCountChar_string (const char * str );

4. Write the code to find the occurrence times of the substring in the parent string: int subNum_string (const char * str, const char * substring );

5. Compile a function to shift n loops of a char string to the right. For example, if the original is "abcdefghi", if n = 2, it should be "hiabcdefgh": void loopMoveNum (char * pStr, int steps );

6. Find the longest symmetric string in the string: Start from the longest -- char * maxLenHuiwen (char * pStr );

7. Calculate the number of symmetric strings in the string and the longest symmetric string): int countHuiwen (const char * pStr );

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1. Write a function int fun (char * p) to determine whether a string is a background bool isHuiwen (const char * str );

// (Str [I], str [len-1-i]) Compare bool isHuiwen (const char * str) {///1 in the form of a character array. // Assert (str! = NULL); // bool isTrue = true; // int len = strlen (str); // for (int I = 0; I <len/2; I ++) // {// if (str [I]! = Str [len-1-i]) // {// cout <"bushi huiwen" <endl; // isTrue = false; // break; ///} // return isTrue; // 2 use the pointer format. Assert (str! = NULL); bool isTrue = true; int len = strlen (str); char * q = (char *) str + len-1; // for pointers with const, the form (cahr *) is required. While (str <q) {if (* str! = * Q) {isTrue = false; cout <"bushi huiwen" <endl; break;} str ++; q --;} return isTrue ;}

2 string reverse order: char * inverseString (char * str );

// (Str [I], str [len-1-i]) Exchange char * inverseString (char * str) {// 2 using the pointer form. // Assert (str! = NULL); // int len = strlen (str); // char * q = (char *) str + len-1; // for pointers with const, the form (cahr *) is required. // Char * add = str; // char tmp; // while (str <q) // {// tmp = * str; // * str = * q; // str ++; // move closer to the center. // Q --; //} // cout <"the converted string is:" <add; // return add; assert (str! = NULL); int len = strlen (str); char tmp, * add = str; for (int I = 0; I <len/2; I ++) {tmp = str [I]; str [I] = str [len-1-i]; str [len-1-i] = tmp;} cout <"the converted string is: "<add <endl; return add ;}

3. Find the character with the highest frequency in the string: char maxCountChar_string (const char * str );

// Integration can be implemented using map and so on.) char maxCountChar_string (const char * str) {assert (str! = NULL); int allchar [26] = {0}; // assume 26 lower-case letters. What about other letters ??? Important: int maxNum = 1; char * t = (char *) str, maxchar = * str; while (* t! = '\ 0') {allchar [* t-'a'] ++; if (allchar [* t-'a']> maxNum) {maxchar = * t; maxNum = allchar [* t-'a'];} t ++ ;} cout <"The max number of char is" <maxchar <"---" <maxNum <endl; return maxchar ;}

4. Write down the occurrence times of the substring in the parent string: int subNum_string (const char * str, const char * substring );

// Add the counting function based on String Matching: recursive can be used, right ??? Int subNum_string (const char * src, const char * dest) {assert (src! = NULL & dest! = NULL); int len1, len2; len1 = strlen (src); len2 = strlen (dest); int count = 0; for (int I = 0; I <len1; I ++) {for (int j = 0; j <len2; j ++) {if (src [I + j]! = Dest [j]) {break; // just roll out the inner loop} if (j = len2-1) {// I + len2-1 = I + j/* printf ("The location is % d -- % d \ n", I, I + j); */count ++; cout <"no." <count <"string location" <I <"--" <I + j <endl; j = 0; break; // jump out of the cycle of the inner layer; otherwise, the wireless loop goes down. }}cout <"Total" <count <"String !!! "<Endl; return count ;}

5. Compile a function to shift n loops of a char string to the right. For example, if the original is "abcdefghi", if n = 2, it should be "hiabcdefgh": void loopMoveNum (char * pStr, int steps );

Void loopMoveNum (char * pStr, int steps) {// 1 memcpy: 1. Move the front of tmp 2 to the back of tmp and add the position. // Int lenRest = strlen (pStr)-steps; // char * tmp; // tmp = (char *) malloc (steps + 1) * sizeof (char )); // assert (tmp! = NULL); // heheei123 ---- 123 (tmp) ---- heh heheei (pStr) ---- 123 heheei (pStr) // memcpy (tmp, pStr + lenRest, steps ); // memcpy (pStr + steps, pStr, lenRest); // memcpy (pStr, tmp, steps); // free (tmp); // tmp = NULL; // cout <"the string after right movement is" <pStr <endl; // 2 is obtained using strcpy. Int lenRest = strlen (pStr)-steps; char * tmp; tmp = (char *) malloc (steps + strlen (pStr) + 1) * sizeof (char )); assert (tmp! = NULL); // heheei123 ---- 123 (tmp) ---- 123 heheei123 (tmp) ---- 123 heei strcpy (tmp, pStr + lenRest); strcpy (tmp + steps, pStr ); * (tmp + strlen (pStr) = '\ 0'; strcpy (pStr, tmp); free (tmp); tmp = NULL; cout <"the string after right movement is" <pStr <endl ;}

6. Find the longest symmetric string in the string: Start from the longest -- char * maxLenHuiwen (char * pStr );

// Start from the longest start. If you know it, exit the loop and save the starting position and length. Char * maxLenHuiwen (char * pStr) {assert (pStr! = NULL); int lenStr = strlen (pStr); if (lenStr = 1) {cout <"only one character, dear !! "<Endl; return pStr;} char * tmp; // stringProcess strProc; for (int n = lenStr; n> 1; n --) {for (int m = 0; m <= lenStr-n; m ++) {tmp = new char [n + 1]; memcpy (tmp, pStr + m, n); * (tmp + n) = '\ 0'; // strProc. strncpy1 (tmp, pStr + m, n); // use a self-compiled class, which is of great significance. If (isHuiwen (tmp) {cout <"the largest symmetric string is" <tmp <", and the length is" <n <endl; return tmp ;}} // delete [] tmp;} cout <"sorry, no symmetric string found !!! "<Endl; return NULL ;}

7. Calculate the number of symmetric strings in the string and the longest symmetric string): int countHuiwen (const char * pStr );

// From small to large, or from large to small): Find the number of one added, instead of break; int countHuiwen (const char * pStr) {assert (pStr! = NULL); int count = 0; int len = strlen (pStr); if (len = 1) {cout <"only one character, dear !! "<Endl; return 1;} char * tmp; for (int num = 2; num <= len; num ++) // num: length of symmetric string {for (int m = 0; m <= len-num; m ++) {tmp = new char [num + 1]; // memcpy (tmp, pStr + m, num); strncpy (tmp, pStr + m, num); * (tmp + num) = '\ 0'; if (isHuiwen (tmp )) {count ++; cout <"no." <count <"symmetric string is" <tmp <", starting from" <m <", the length is <num <endl ;}delete [] tmp ;}cout <"the number of symmetric strings is:" <count <endl; return count ;}

Test code

int main(){    //char str[]="heeheei123";    //isHuiwen(str);    //inverseString(str);    /*maxCountChar_string(str);*/    /*char str1[]="hahahanihaohah";    char str2[]="hah";    subNum_string(str1,str2);*/    //loopMoveNum(str,3);    char str[]="heehee";    //maxLenHuiwen(str);    countHuiwen(str);    return 0;}