C + + string manipulation Pen Test second wave

//1. String substitution spaces: Implement a function that replaces each space in a string with "%20". //For example, enter "We are happy.", then output "we%20are%20happy." #include <iostream>#include <assert.h>#include <string.h>using namespace STD;Char* Grial (Char*s) {assert (s! = NULL);intLen =strlen(s);intCount =0;//Count the number of spaces.     Char*p = s; while(*p! =' + ')    {if(*p = ="') count++;    p++; }intn = len + count *2+1;Char*str =New Char[n];Char*ret = str;memset(STR,' + ', n);strcpy(str,s);//Copy the original string into the new string array. p = str + N-1;Char*q = str + len; while(Q < P) {if(*q = ="') {*p--=' 0 '; *p--=' 2 '; *p ='% '; }Else{*p = *q;        } q--;    p--; }returnRet }intMain () {CharS[] ="We are happy";cout<<grial (s) <<endl;return 0;}//2. Determines whether a string is a string after the rotation of another string. ///For example: given S1 = AABCD and S2 = Bcdaa, return 1, given S1 = ABCD//And S2 = ACBD, returns 0.#include <iostream>#include <assert.h>using namespace STD;BOOLGrial (Const Char*STR1,Const Char*STR2) {assert (str1!=null&&str2!=null);Const Char*p = str1;Const Char*q = str2 +strlen(STR2)-1;if(strlen(str1)! =strlen(STR2))return 0; while(*p! =' + ')    {if(*p! = *q)return 0;        p++;    q--; }return 1;}intMain () {CharS1[] ="ABCD";CharS2[] ="DCBA";cout<< grial (S1, S2) << Endl;return 0;} *///3. Defines the left rotation of a string: moves several characters in front of the string to the end of the string. //such as String abcdef left rotation 2 bit to get string cdefab. Please implement the function of string left rotation. //requires that the complexity of the string operation with length n is O (n) and the auxiliary memory is O (1). #include <iostream>#include <assert.h>using namespace STD;voidSwap (Char*P1,Char*P2) {CharTemp while(P1 < P2)        {temp = *P1;        *P1 = *P2;        *P2 = temp;        p1++;    p2--; }}voidGrial (Char*s,intN) {assert (s!=null);intLen =strlen(s);Char*p = s + Len-1;Char*q = s;Char*midchar = NULL; Swap (Q,P);//First overall reverse. Midchar = p-n+1;//Then split into two parts in reverse order. Swap (q,midchar-1); Swap (midchar,p);}intMain () {CharS[] ="ABCdef"; Grial (s),3);cout<< s << Endl;return 0;} *///4. Finding substrings: Simulating the implementation of the STRSTR function. #include <iostream>#include <assert.h>#include <string.h>using namespace STD;intMy_atoi (Char*P1,Char*P2) {intCount =0; while(P1 <= p2) {count = Count *Ten+ *P1-' 0 ';    p1++; }returnCount;}Char* MY_STRSTR (Char*dist,Char*SRC) {intn =strlen(SRC);intNUM1 = My_atoi (src,src+n-1);intFlags = num1% -;//Mark.     Char*p = dist;Char*q;Char*m; while(P <= Dist +strlen(Dist)-N) {m=p;if(*p = = *src) {if(My_atoi (p, p + N-1) % -= = Flags) {q = src; while(*q! =' + '&& *p!=' + ')                {if(*q! = *p) Break;                    q++;                p++; }if(*q = =' + ')returnM        }} m++;    P=m; }returnNULL;}intMain () {CharS1[] ="123456789";CharS2[] ="789";cout<<my_strstr (S1, S2) <<endl;return 0;}//5. Simulate the Atoi function that implements the library function. #include <iostream>#include <assert.h>using namespace STD;BOOLIsnum (CharCH) {if(CH-' 0 ') >=0&& (CH-' 0 ') <=9)return true;return false;}intGetnum (Const Char*s) {Const Char*p = s;intCount =0; while(*p! =' + ')    {if(*p = ='. ')returnCountif(count<0)return 2147483647; Count = Count *Ten+ *p-' 0 ';    p++; }}intMy_atoi (Const Char*s) {assert (s! = NULL);Charch = *s;CharFlagsif(Isnum (ch)) flags = Isnum (CH) +' 0 ';ElseFlags = CH;Const Char*p = s +1;Switch(flags) { Case' + ':returnGetnum (P); Break; Case '-':if(Getnum (p) = =2147483647)return 0-Getnum (p)-1;return 0-Getnum (p); Break; Case ' 1 ':returnGetnum (s); Break;default:Exit(2); }return 0;}intMain () {cout<< My_atoi (" -31321312321321") << Endl;return 0;}#include <iostream>#include <assert.h>using namespace STD;//Implement a memmove on your own, and take a deep look at memory coverage issues. void* My_memmove (void*dist,void*SRC,intLen) {assert (dist!=null&&src!=null);Char*pdist = (Char*) Dist;void*ret = dist;Char*PSRC = (Char*) src;if(pdist <= psrc | | psrc + len <= pdist) { while(len--)        {*pdist++ = *psrc++; }returnRet }Else{pdist + = len-1; PSRC + = Len-1; while(len--)        {*pdist--= *psrc--; }returnRet }}intMain () {intA[] = {2,3,4, $,1,6,7}; My_memmove (A +1A8);int*b =New int[7]; My_memmove (B,a, -);inti =0; for(; I <4; i++) {cout<< B[i] <<"  "; }inti =0; for(; I <7; i++) {cout<< A[i] <<"  "; }cout<< Endl;return 0;}#include <iostream>#include <assert.h>using namespace STD;voidMy_memcopy (void*a,Const  void*b,intLen) {assert (A! = Null&&b = NULL);Char*p = (Char*) A;Char*q = (Char*) b; while(len--)    {*p++ = *q++; }}intMain () {intA[] = {1,2,3,4,5};int*b =New int[5]; My_memcopy (b, A,sizeof(a));inti =0; for(; I <5; i++) {cout<< B[i] << Endl; }memcpy(B,a, -);return 0;}

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C + + string manipulation Pen Test second wave