阿里笔试第一题

 在S中查找T的序列，对于当前S[i]，如果不等于T[j]，那么让i+1，最后判断下-1的情况就ok了

 

/// file :: 2jjalloc.h
#ifndef _JJALLOC_
#define _JJALLOC_

#include<new>/// for placement new
#include<cstddef>/// for ptrdiff_t,size_t;
#include<cstdlib>/// for exit()
#include<climits>/// for unit_max
#include<iostream>///for cerr

#endif
namespace JJ
{
    template <class T>
    inline T* _allocate(ptrdiff_t siz,T *) {
        std::set_new_handler(0);
        T* tmp = (T*)(::operator new ((size_t)(siz*(sizeof(T)))));
        if(!tmp){
            std::cerr<<"out of merry"<<std::endl;
            exit(1);
        }
        return tmp;
    }
    template <class T>
    inline void _delallocate(T*buffer){
        ::operator delete(buffer);
    }
    template <class T>
    inline void _destory(T* tmp){
           tmp->~T();
    }
    template <class T1,class T2>
    inline void _construct(T1 *p,const T2& val){
         new (p) T1(val);
    }
}


#include<bits/stdc++.h>
using namespace std;
map<char,int>mp;
int main() {
    string str1,str2;
    cin>>str1>>str2;
    int i=0,j=0;
    for(i=0;i<str1.size();++i){
        if(str1[i]==str2[j])++j;
        else mp[str1[i]]++;
    }
    int ans=str1.size()-j;
    for(j;j<str1.size();++j){
        mp[str2[j]]--;
        if(mp[str2[j]]<0)ans=-1;
    }
    cout<<ans;
    return 0;
}