16进制的string转unsigned long long

16进制的string转unsigned long long

(尽可能使用int或long long)。 windows下int long longlong 4 4 8 linux下int long longlong 4 8 8

#include<bits/stdc++.h> 
using namespace std;

unsigned long long h2ll(std::string h)
{
    unsigned long long ans = 0;
    // remove 0x 
    if(h.size()>=2&&h[0]=='0'&&h[1]=='x')
    {
        std::string t="";
        for(int i=2;i!=h.size();i++)
        {
            t+=h[i];
        }
        h=t;
    }
    unsigned long long radix = 1;
    char index[17]="0123456789abcdef";
    bool flag=1;
    for(int i=h.size()-1;i>=0;i--)
    {
        int j=0;
        for(j=0;j!=16;j++)
        {
            if(h[i]==index[j])
            {
                ans+=j*radix;
                break;
            }
            if(j>9&&h[i]==(index[j]-32))
            {
                ans+=j*radix;
                break;
            }
        }
        if(j==16)
        {
            flag=0;
            break;
        }
        radix<<=4;
    }
    if(!flag)
    {
        ans=0;
    }
    return ans;
}

int main()
{

    char a[100]="0x7fba905cc010";
    string str = a;
    cout<<str<<endl;
    unsigned long long addr=h2ll(str);
    printf("%p\n", addr);

    return 0;
}