求字符串中数字字符转换成数字之后的总和

#include<iostream>
#include<stdio.h>
using namespace std;
int SumString(char *r)
{
char *p = r;
if (p == NULL)
return -1;
char *q = p;
int sum = 0;
while(*p != '\0')
{

while(*p > '9'|| *p < '0' && *p != '\0')
{
p++;
q++;
}

while(*q >= '0'&& *q <= '9')
q++;

int su = 0;
while(p != q)
{
su = su *10 + (*p - '0');
p++;
}
sum  = sum + su;
p = q;
}
return sum;
}
void main()
{
char *str = "5ab5cb345bj10k~";
int m = SumString(str);
printf("%d\n",m);
}