include <string.h> include <ctype.h> define M 80 int main(){ char s[M];int len,flag;int i,j;printf("输入个数少于%d的字符串\n",M);gets(s);len=strlen(s);if(len>M){ printf("超过长度\n");return 1;} for(i=0,j=0;i<len;i++){ s[j]=s[i];if(isalnum(s...