数据结构与算法之 字符串

#include<iostream>using namespace std;int main(void){    char * p="abc";    char a[]="bdc";    cout<<strcmp(p,a)<<endl;    return 0;}#include<stdio.h>#include<string.h>int main(void){    char a[64] ;    char  p[64] = "hello";    char * q = "world!";    char w[]="he llo world!";    char * ret =strcpy(a,p);    char * ret1 =strcat(p,q);    char * ret2 = strstr(p,q);    char * buf = strtok(w," ");    printf("%s\n%s\n%s\n%s\n",ret,ret1,ret2,buf);    return 0;}//输入一行字符，统计其中有多少个单词，单词之间用空格分隔开。#include<iostream>#include <string>using namespace std;int main(void){    int i = 0,sum=1;    /*string ch;    getline(cin,ch);*/    char ch[64];    gets(ch)    cout<<ch<<endl;    while (1)    {        if(ch[i]==NULL)            break;        if (ch[i]==' ')//空格这一个字符要用单引号        {            sum++;        }        i++;    }    cout<<"The number of words is:"<<sum<<endl;    return 0;}//有3个字符串，要求找出其中的最大者#include<iostream>#include <string>using namespace std;int main(void){    /*string ch1,ch2,ch3,max;    getline(cin,ch1);    getline(cin,ch2);    getline(cin,ch3);    swap(max,ch1);    if(ch1.compare(ch2)<0)        swap(max,ch2);    if(max.compare(ch3)<0)        swap(max,ch3);    cout<<"The maxium string is:"<<max<<endl;*/    char max[20];    char ch[3][20];//数组元素是[0][1][2]  没有[3]    int i;    for (i=0;i<=2;i++)    {        gets(ch[i]);    }    strcpy(max,ch[0]);    if (strcmp(ch[0],ch[1])<0)        strcpy(max,ch[1]);    if(strcmp(max,ch[2])<0)        strcpy(max,ch[2]);    cout<<max<<endl;    return 0;}