字符串合并处理

#include<bits/stdc++.h>using namespace std;char change(char c){    int flag=0;    if(c<='9'&&c>='0')    {        c=c-'0';        flag=1;    }    else if(c<='f'&&c>='a')    {        c=c-'a'+10;        flag=1;    }    else if(c<='F'&&c>='A')    {        c=c-'A'+10;        flag=1;    }    if(flag==1)    {        int temp=c;        int sum=0,k=8;        while(temp)        {            sum+=(temp%2)*k;            k/=2;            temp/=2;        }        if(sum>=10)c=(sum-10)+'A';        else c=sum+'0';    }    return c;}void ProcessString(char* str1,char *str2,char * strOutput){    char u[10000],a1[10000],a2[10000];    sprintf(u,"%s%s",str1,str2);    int num1=0,num2=0;    for(int i=0; u[i]!='\0'; i++)    {        if(i%2==0)        {            a1[num1++]=u[i];        }        else        {            a2[num2++]=u[i];        }    }    sort(a1,a1+num1);    sort(a2,a2+num2);    for(int i=0; i<num1; i++)        a1[i]=change(a1[i]);    for(int i=0; i<num2; i++)        a2[i]=change(a2[i]);    int n=0;    for(n=0; n<num1+num2; n++)    {        if(n%2==0)strOutput[n]=a1[n/2];        else strOutput[n]=a2[n/2];    }    strOutput[n]='\0';}int main(){    char  str1[10000],str2[10000],strOutput[10000];    while(scanf("%s%s",str1,str2)!=EOF)    {        ProcessString(str1,str2,strOutput);        printf("%s\n",strOutput);    }    return 0;}