第八周【串】项目3-顺序串算法

头文件：

#ifndef SqString_H_INCLUDED#define SqString_H_INCLUDED#define MaxSize 100             //最多的字符个数typedef struct{   char data[MaxSize];         //定义可容纳MaxSize个字符的空间    int length;                 //标记当前实际串长} SqString;void StrAssign(SqString &s,char cstr[]);    //字符串常量cstr赋给串svoid StrCopy(SqString &s,SqString t);   //串t复制给串sbool StrEqual(SqString s,SqString t); //判串相等int StrLength(SqString s);  //求串长SqString Concat(SqString s,SqString t);  //串连接SqString SubStr(SqString s,int i,int j); //求子串SqString InsStr(SqString s1,int i,SqString s2); //串插入SqString DelStr(SqString s,int i,int j) ;   //串删去SqString RepStr(SqString s,int i,int j,SqString t);     //串替换void DispStr(SqString s);   //输出串#endif // SqString_H_INCLUDED

（1）试编写算法实现将字符串S中所有值为c1的字符换成值为c2的字符：

#include <stdio.h>#include "sqString.h"void Trans(SqString &s, char c1, char c2){    int i;    for (i=0; i<s.length; i++)        if (s.data[i]==c1)            s.data[i]=c2;}int main(){    SqString s;    StrAssign(s, "messages");    Trans(s, 'e', 'a');    DispStr(s);    return 0;}

（2）试编写算法，实现将已知字符串所有字符倒过来重新排列。如ABCDEF改为FEDCBA：

#include <stdio.h>#include "sqString.h"void Invert(SqString &s){    int i;    char temp;    for (i=0; i<s.length/2; i++)    {        temp = s.data[i];        s.data[i]=s.data[s.length-i-1];        s.data[s.length-i-1] = temp;    }}int main(){    SqString s;    StrAssign(s, "abcdefg");    Invert(s);    DispStr(s);    return 0;}

（3）从串s中删除其值为c的所有字符。如message中删除‘e’，得到的是mssag：

#include <stdio.h>#include "sqString.h"void DellChar(SqString &s, char c){    int k=0, i=0;   //k记录值等于c的字符个数    while(i<s.length)    {        if(s.data[i]==c)            k++;        else            s.data[i-k]=s.data[i];        i++;    }    s.length -= k;}int main(){    SqString s;    StrAssign(s, "message");    DellChar(s, 'e');    DispStr(s);    return 0;}

（4）有两个串s1和s2，设计一个算法求一个这样的串，该串中的字符是s1和s2中公共字符。所谓公共子串，是由在s1中有，且在s2中也有的字符构成的字符。例s1为”message”，s2为”agent”，得到的公共子串是”eage”。 

#include <stdio.h>#include "sqString.h"SqString CommChar(SqString s1,SqString s2){    SqString s3;    int i,j,k=0;    for (i=0; i<s1.length; i++)    {        for (j=0; j<s2.length; j++)            if (s2.data[j]==s1.data[i])                break;        if (j<s2.length)            //s1.data[i]是公共字符        {            s3.data[k]=s1.data[i];            k++;        }    }    s3.length=k;    return s3;}int main(){    SqString s1, s2, s;    StrAssign(s1, "message");    StrAssign(s2, "agent");    s = CommChar(s1, s2);    DispStr(s);    return 0;}