C++中string查找和取子串和整形转化

1.string.find函数

 #include <iostream>
 #include <string>
 using namespace std;

 /* run this program using the console pauser or add your own getch, system("pause") or input loop */

 int main(int argc, char** argv) {

     string s;
     string str;
     char *p = "abc";

     int index;

     getline(cin,s);
     cout<<"s="<<s<<endl;

     getline(cin,str);
     cout<<"str="<<str<<endl;

     index = s.find(str);
     cout<<"char index="<<index<<endl;

     index = s.find(p);
     cout<<"string index="<<index<<endl;

     return ;
 }

2. 取子串

#include <iostream>
#include <string>
#include <vector>
#include <stdlib.h>
using namespace std;

//输入2015-10-22
int riqi(string str){
    int i = ;
    int year;
    int month;
    int day;
    int i_start,i_end;
    string tmp;

    i_start = str.find("-");//第一个'-'
    tmp = str.substr(,i_start);//取从0下标开始的i_start个字符
    year = atoi(tmp.c_str());//tmp.c_str()转化为C语言中字符串指针

    i_end = str.rfind("-");//最后一个'-'
    tmp = str.substr(i_start+,i_end - i_start);
    month = atoi(tmp.c_str());

    tmp = str.substr(i_end+);
    day = atoi(tmp.c_str());
    cout<<year<<" "<<month<<' '<<day<<endl;
    //输出的结果为  2015 10 22
    return ;
}