foo.cc: In function 'int main()':
foo.cc:14:2: error: 'mamset' was not declared in this scope
  mamset (c,0,sizeof(c));
  ^~~~~~
foo.cc:14:2: note: suggested alternative: 'memset'
  mamset (c,0,sizeof(c));
  ^~~~~~
  memset
foo.cc:16:16: warning: left operand of comma operator has no effect [-Wunused-value]
  for(int i=0;i,la;i++){
                ^~
foo.cc:18:10: error: invalid operands of types 'int' and 'int [101]' to binary 'operator*'
    f=a[i]*b{j};jw=f/10;f%10;//处理逐位乘，记录乘积和进位
      ~~~~^~
foo.cc:18:25: warning: statement has no effect [-Wunused-value]
    f=a[i]*b{j};jw=f/10;f%10;//处理逐位乘，记录乘积和进位
                        ~^~~
foo.cc:6:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s",sa);
  ~~~~~^~~~~~~~~
foo.cc:7:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s",sa);
  ~~~~~^~~~~~~~~

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