int compare(char* dest,char* src)

09年华赛在成都的两道试题。

 

C语言实现：

[1]

给出一个函数，原型为 int compare(char* dest,char* src)
要求比较两个字符串(由dest与src字符指针标识)
1，如果两字符串所含字母完全相同，则逆序输出字符串并返回0；
2，如果两字符串所含字母相同(不区分大小写；A与a也算字母相同) ，则返回1 ；
3，否则返回3 。

[2]
文件data.in中保存有m (m < 2000) 个数据行，每行最多包含25个由空格分隔的正整数。给出整数k(k <26)，计算文件中第k列所有数据的最大值、最小值和平均值。最大值和最小值以整数格式输出，平均值保持两位小数。若某行的列数小于k，则认为该行第k列的值为0。 

 

问题来源：http://topic.csdn.net/u/20090220/17/afc59963-c997-4215-8a68-428acbc8c752.html

 

第一题我的解法如下：

/* * 字符串比较 * 2010-3-15 wcdj*/#include <stdio.h>#include <iostream>#include <assert.h>int compare(char* dest,char* src);void rprint(char* s);int main(){// testchar* str0=0;char* str1="wcdj";char* str2="wcdj";char* str3="WcDj";char* str4="wcdj is a guy.";char* str5="I am wcdj";char str6[]="wcdj";char str7[]="WcDj";char str8[]="Oops";printf("2: %d/n",compare(str1,str2));//printf("0 %d/n",compare(str1,str0));printf("3: %d/n",compare(str1,str3));printf("4: %d/n",compare(str1,str4));printf("5: %d/n",compare(str1,str5));printf("6: %d/n",compare(str1,str6));printf("7: %d/n",compare(str1,str7));printf("8: %d/n",compare(str1,str8));return 0;}void rprint(char* s){int nLen=0;char* s_temp=s;while (*s_temp++!='/0'){++nLen;}int i;for (i=nLen-1;i>=0;--i){printf("%c",s[i]);// same as below//printf("%c",*(s+i));}printf("/n");}int compare(char* dest,char* src){char* dest_temp=dest,*src_temp=src;bool bCapital=false;// checkassert(dest && src);// same stringif (dest==src){// 逆序输出字符串rprint(dest);return 0;}while(*dest!='/0' && *src!='/0'){if (*dest!=*src){if ((*dest>='a' && *dest<='z' && *dest==*src+32) || (*src>='a' && *src<='z' && *src==*dest+32)){bCapital=true;} else{return 3;}}++dest;++src;}if (*dest=='/0' && *src=='/0'){if (bCapital){return 1;} else{// 逆序输出字符串rprint(dest_temp);return 0;}}else{return 3;}}/*输出：jdcw2: 03: 14: 35: 3jdcw6: 07: 18: 3Press any key to continue*/

 

上述逆序输出字符串改用栈的方法如下：

/* * 字符串比较 * 2010-3-15 wcdj*/#include <stdio.h>#include <iostream>#include <assert.h>#include <stack>using namespace std;// 使用stack的时候必须包含此句int compare(char* dest,char* src);void rprint(char* s);int main(){// testchar* str0=0;char* str1="wcdj";char* str2="wcdj";char* str3="WcDj";char* str4="wcdj is a guy.";char* str5="I am wcdj";char str6[]="wcdj";char str7[]="WcDj";char str8[]="Oops";printf("2: %d/n",compare(str1,str2));//printf("0 %d/n",compare(str1,str0));printf("3: %d/n",compare(str1,str3));printf("4: %d/n",compare(str1,str4));printf("5: %d/n",compare(str1,str5));printf("6: %d/n",compare(str1,str6));printf("7: %d/n",compare(str1,str7));printf("8: %d/n",compare(str1,str8));return 0;}void rprint(char* s){// 用栈实现逆序输出 stack<char> cstack;// 将数组中的元素一次压入栈顶//while(*s++!='/0')// errorwhile(*s!='/0')// ok{cstack.push(*s++);}//printf("%d/n",cstack.size());// 依次将元素从栈顶输出while(!cstack.empty()){printf("%c",cstack.top());// 删除当前栈顶元素cstack.pop();}printf("/n");}int compare(char* dest,char* src){char* dest_temp=dest,*src_temp=src;bool bCapital=false;// checkassert(dest && src);// same stringif (dest==src){// 逆序输出字符串rprint(dest);return 0;}while(*dest!='/0' && *src!='/0'){if (*dest!=*src){if ((*dest>='a' && *dest<='z' && *dest==*src+32) || (*src>='a' && *src<='z' && *src==*dest+32)){bCapital=true;} else{return 3;}}++dest;++src;}if (*dest=='/0' && *src=='/0'){if (bCapital){return 1;} else{// 逆序输出字符串rprint(dest_temp);return 0;}}else{return 3;}}/*输出：jdcw2: 03: 14: 35: 3jdcw6: 07: 18: 3Press any key to continue*/

 

与我想法基本一样的一位朋友(riceli)的代码，看起来更规范点儿：

#include <assert.h>#include <stdio.h>#define CHAR_a 0x61#define CHAR_A 0x41#define JUDGE_CHAR(x) (((x) >= 'a' && (x) <= 'z') || ((x) >= 'A' && (x) <= 'Z'))#define RE_EQ 0#define RE_IGNOR 1#define RE_NO 3int MyStrcmp(char *dst, char *src){ int flag = 0; assert(dst); assert(src); while(*dst != '/0' && *src != '/0') { if (*dst != *src) { if (1 != JUDGE_CHAR(*dst) || 1 != JUDGE_CHAR(*src)) { return RE_NO; } else { if ((int)*dst - (int)*src == 0x20 || (int)*dst - (int)*src == -0x20) { flag = 1; } else { return RE_NO; } } } dst++; src++; } if (*dst != '/0' || *dst != '/0') { return RE_NO; } if (1 == flag) return RE_IGNOR; return RE_EQ;}int main(int argc, char* argv[]){ printf("%d/n", MyStrcmp("wcDj", "wcda"));// 3 return 0;}

 

若使用库函数的方法：

/*使用strcmp,stricmp函数*/#include <iostream>using namespace std;int compare(char* dest,char* src){ if (strcmp(dest,src)==0) { return 0; } else if(stricmp(dest,src)==0) { return 1; } else { return 3; }}int main(int argc, char* argv[]){ char *s0="abcd"; char *s1="abcd";char *s2="aBcD"; char *s3="Accd";char *s4="abcde";char *s5="aDcdef";printf("%d/n",compare(s0,s1));// 0printf("%d/n",compare(s0,s2));// 1printf("%d/n",compare(s0,s3));// 3printf("%d/n",compare(s0,s4));// 3printf("%d/n",compare(s0,s5));// 3 return 0;}

 

等价于：

/*使用strcpy,strcmp,strupr函数*/#include <iostream>using namespace std;int compare(const char *dest, const char *src){ // 修改为可写char desttmp[128],srctmp[128];strcpy(desttmp,dest);strcpy(srctmp,src);if (strcmp(desttmp,srctmp)==0) return 0; // strupr将串中的小写字母转换为大写字母(注意：必须是变量)/*还可以使用函数toupper 功 能: 把字符转换成大写字母 用 法: int toupper(int c);*/ if (strcmp(strupr(desttmp),strupr(srctmp))==0) return 1; return 3;}int main(int argc, char* argv[]){ char *s0="abcd"; char *s1="abcd";char *s2="aBcD"; char *s3="Accd";char *s4="abcde";char *s5="aDcdef";printf("%d/n",compare(s0,s1));// 0printf("%d/n",compare(s0,s2));// 1printf("%d/n",compare(s0,s3));// 3printf("%d/n",compare(s0,s4));// 3printf("%d/n",compare(s0,s5));// 3 return 0;}

 

上面的库函数由自己实现：

#include <stdio.h>#include <assert.h>// 相等返回0，不等返回1int _mystrcmp(char* dest,char* src){// checkassert(dest && src);// same stringif(dest == src)return 0;while(*dest != NULL && *src != NULL){ if(*dest++ == *src++) continue; else return 1;}// compare allif (*dest==NULL && *src==NULL){return 0;} else{return 1;}}char* _mytoupper(char* s){ char *stmp = s;while(*stmp!=NULL){if (*stmp>='a' && *stmp<='z')// make lowercase to uppercase{*stmp -= 0x20;}++stmp;}return s;}int compare(char* dest,char* src) {if(_mystrcmp(dest,src)==0)// equal all{return 0;} else if(_mystrcmp(_mytoupper(dest), _mytoupper(src))==0)// equal not including upper&lowercase{return 1;} else// different{return 3;} }int main(){ char s0[]="abcd"; char s1[]="abcd";char s2[]="aBcD"; char s3[]="Accd";char s4[]="abcde";char s5[]="aDcdef";printf("%d/n",compare(s0,s1));// 0printf("%d/n",compare(s0,s2));// 1printf("%d/n",compare(s0,s3));// 3printf("%d/n",compare(s0,s4));// 3 printf("%d/n",compare(s0,s5));// 3 return 0;}

 

使用标准库string类型比较字符串：

 /* * 使用标准库string类型比较字符串 * string类定义了6个关系操作符：<,<=,>,>=,==,!= * 这些操作符实际上是比较每个string对象的字符 * * 2010-3-23 wcdj add this*/#include <iostream>#include <string>#include <cstring>using std::cin;using std::cout;using std::endl;using std::string;int compare(char* dest,char* src);int main(){char s0[]="wcdj";// 0x0012ff78char s1[]="wcdj";// 0x0012ff70char s2[]="WcDj"; char s3[]="nihao";// testcout<<"s0,s1: "<<compare(s0,s1)<<endl;// 0cout<<"s1,s2: "<<compare(s1,s2)<<endl;// 1cout<<"s1,s3: "<<compare(s1,s3)<<endl;// 2return 0;}int compare(char* dest,char* src) {if (dest==src){return 0;}string strDest(dest),strSrc(src);if (strDest!=strSrc)// !={// c_str返回C风格字符串，返回的指针指向const char类型数组// strupr将串中的小写字母转换为大写字母(注意：必须是变量)，返回char*// const_cast<char*>转换掉对象的const属性strDest=strupr(const_cast<char*>(strDest.c_str()));strSrc=strupr(const_cast<char*>(strSrc.c_str()));if (strDest==strSrc){return 1;} else{return 2;}} else{return 0;}}

 第二题待续...