//整数转化为字符串数 && 字符串数转化为整数
#include
#include
#include
using namespace std;
void itoa()
{
int num = 0;
int i = 0;
int j = 0;
char a[100];
char b[100];
if(num == 0)
a[i++] =0+'0';
while(num)
{
a[i++] = num+'0';
num /= 10;
}
i = i-1;
while(i>= 0)
b[j++] =a[i--];
b[j] = '\0';
cout<< b <<endl;
}
void atoi()
{
chars[] = " -34";
int i= 0;
intsign = 1;
intsum = 0;
if(s[i] == ' ' || s[i] == '\t')
i++;
if(s[i] == '+')
{
sign = 1;
i++;
}
elseif(s[i] == '-')
{
sign = -1;
i++;
}
while(s[i] != '\0')
sum =sum*10+(s[i++]-'0');
cout<< sum*sign<< endl;
}
int main(int argc, char *argv[])
{
itoa();
atoi();
system("PAUSE");
returnEXIT_SUCCESS;
}
//strcpy函数
#include <cstdlib>
#include <iostream>
using namespace std;
char *strcpy(char *b, char *a)
{
assert((a != NULL)&& (b != NULL));
char*address = b;
while((*b++ = *a++) != '\0');
returnaddress;
}
int main(int argc, char *argv[])
{
char a[] = "I loveBoat";
char b[100];
char *address =strcpy(b, a);
int length =strlen(address);
cout<< address<< endl;
cout<< length<< endl;
system("PAUSE");
returnEXIT_SUCCESS;
}
//将一个字符串向右移动两位：考察memcpy，strcpy，memset等库函数的使用。
#include <cstdlib>
#include <iostream>
using namespace std;
char *loopmove(char *str, int steps)
{
int n= strlen(str)-steps;
chartemp[100];
memcpy(temp, str+n, steps);
memcpy(temp+steps, str, n);
temp[strlen(str)] = '\0';
cout<< temp<< endl;
}
int main(int argc, char *argv[])
{
char a[] ="abcdefghi";
loopmove(a, 2);
system("PAUSE");
returnEXIT_SUCCESS;
}
//输入一行字符串，找出其中出现的相同且长度最长的字符串
#include <cstdlib>
#include <iostream>
#include <string>
using namespace std;
int main(int argc, char *argv[])
{
string a ="yyabcdabjcabceg";
string temp;
int max = 0;
stringfin;
for(int i = a.length();i >= 0; i--)
{
for(int j= 0; j < a.length(); j++)
{
if(j <= i)
{
int t = 0;
int num = 0;
temp = a.substr(j, i);
//cout << temp<< endl;
t = a.find(temp);
num = a.rfind(temp);
if((t != num) &&(temp.length() > max))
{
max = num-t;
fin = temp;
}
}
}
}
cout<< fin<< " "<< fin.length()<< endl;
system("PAUSE");
returnEXIT_SUCCESS;
}
//实现C++中的strstr()，即把主串中子串及以后的字符全部返回。不使用已有的函数来完成。
#include <cstdlib>
#include <iostream>
#include <string>
using namespace std;
char *strstr(char *a, char *b)
{
for(int i = 0; a[i] !='\0'; i++)
{
int j =0;
if(a[i] ==b[j])
{
int temp = i;
while(a[i++] == b[j++])
{
if(b[j] == '\0')
returna+i-j;
}
i = temp;
}
}
return NULL;
}
int main(int argc, char *argv[])
{
char a[] ="1123412345678";
char b[] = "234";
cout<< strstr(a, b)<< endl;
system("PAUSE");
returnEXIT_SUCCESS;
}
//将一句话里的单词进行倒置，标点符号不倒换。
#include <cstdlib>
#include <iostream>
#include <string>
using namespace std;
int main(int argc, char *argv[])
{
char a[] = "i come fromtianjin.";
int i = 0;
int begin, end;
int j =strlen(a)-1;
char temp;
while(j >i)
{
temp =a[i];
a[i] =a[j];
a[j] =temp;
j--;
i++;
}
i = 0;
while(a[i] !=NULL)
{
if(a[i] != ' ')
{
begin =i;
while(a[i]!= ' ' && a[i] != NULL)
i++;
i = i -1;
end =i;
}
while(begin <end)
{
temp = a[begin];
a[begin] = a[end];
a[end] = temp;
end--;
begin++;
}
i++;
}
cout<< a <<endl;
system("PAUSE");
returnEXIT_SUCCESS;
}
//转换字符串格式为原来字符串里的字符+该字符连续出现的个数。可以使用sprintf()，打印到字符串中。
#include <cstdlib>
#include <iostream>
#include <string>
using namespace std;
int main(int argc, char *argv[])
{
char a[] ="1233422222";
char b[100];
b[0] = '\0';
int len =strlen(a);
int count = 1;
for(int k = 0; k<= len-1; k++)
{
if(a[k+1]== a[k])
{
count++;
}
else
{
sprintf(b+strlen(b), "%c%d",a[k], count);
count = 1;
}
}
cout<< b <<endl;
system("PAUSE");
returnEXIT_SUCCESS;
}
