不用寫成absolute和secgap也可以處理 其實我寫的很多此一句

hint:ASCII中數字轉int實值是-48

→(char)'0'=(int)48

#include <iostream>

#include <string.h>

using namespace std;

int absolute(int a)

{

if (a<0) return (-a);

else return a;

}

int secgap(string num)

{

int leng,odd=0,even=0,i,j;

leng=num.length();

for (i=0;i<leng;i+=2)

odd=odd+num[i]-48;

for (i=1;i<leng;i+=2)

even=even+num[i]-48;

return odd-even; 

}

int main()

{

int a;

string number;

while(cin >> number)

{

cout << absolute(secgap(number)) << endl;

}

return 0;

}