输入一个字符串,输出长型整数。
1long atol(char *str){
2 char *p = str;
3 long l=1;m=0;
4 if (*p=='-') {
5 l=-1;
6 ++p;
7 }
8 while(isDigit(*p)){
9 m = m*10 + p;
10 ++p;
11 }
12 if(!p) return m*l;
13 else return error;
14}
2 char *p = str;
3 long l=1;m=0;
4 if (*p=='-') {
5 l=-1;
6 ++p;
7 }
8 while(isDigit(*p)){
9 m = m*10 + p;
10 ++p;
11 }
12 if(!p) return m*l;
13 else return error;
14}