foo.cc: In function 'void solve(char*, char*)':
foo.cc:7:23: warning: 'sizeof' on array function parameter 's' will return size of 'char*' [-Wsizeof-array-argument]
     int len = sizeof(s) / sizeof(s[0]);
                       ^
foo.cc:5:19: note: declared here
 void solve(char s[], char ans[]) 
                   ^
foo.cc: In function 'int main()':
foo.cc:35:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", s);           //s为要处理的加密字符串，答案储存在ans里
     ~~~~~^~~~~~~~~

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