/in/foo.c:3:6: warning: return type of 'main' is not 'int' [-Wmain]
 void main()
      ^~~~
/in/foo.c: In function 'main':
/in/foo.c:9:18: error: stray '\357' in program
   scanf("%s",s1);；
                  ^
/in/foo.c:9:19: error: stray '\274' in program
   scanf("%s",s1);；
                   ^
/in/foo.c:9:20: error: stray '\233' in program
   scanf("%s",s1);；
                    ^
/in/foo.c: In function 'change':
/in/foo.c:25:30: error: expected ';' before ')' token
  for(i=0;*(a+i)!=0&&*(b+i)!=0);i++)
                              ^
/in/foo.c:25:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(i=0;*(a+i)!=0&&*(b+i)!=0);i++)
  ^~~
/in/foo.c:25:32: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
  for(i=0;*(a+i)!=0&&*(b+i)!=0);i++)
                                ^
/in/foo.c:25:35: error: expected ';' before ')' token
  for(i=0;*(a+i)!=0&&*(b+i)!=0);i++)
                                   ^
/in/foo.c:25:35: error: expected statement before ')' token
/in/foo.c:32:3: warning: statement with no effect [-Wunused-value]
   for(i;*(b+i)!=0);i++)
   ^~~
/in/foo.c:32:18: error: expected ';' before ')' token
   for(i;*(b+i)!=0);i++)
                  ^
/in/foo.c:32:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for(i;*(b+i)!=0);i++)
   ^~~
/in/foo.c:32:20: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   for(i;*(b+i)!=0);i++)
                    ^
/in/foo.c:31:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(a[i]=='\0')
  ^~
/in/foo.c:32:20: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
   for(i;*(b+i)!=0);i++)
                    ^
/in/foo.c:32:23: error: expected ';' before ')' token
   for(i;*(b+i)!=0);i++)
                       ^
/in/foo.c:32:23: error: expected statement before ')' token
/in/foo.c:34:2: error: 'else' without a previous 'if'
  else
  ^~~~
/in/foo.c:35:3: warning: statement with no effect [-Wunused-value]
   for(i;*(a+i)!=0);i++)
   ^~~
/in/foo.c:35:18: error: expected ';' before ')' token
   for(i;*(a+i)!=0);i++)
                  ^
/in/foo.c:35:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for(i;*(a+i)!=0);i++)
   ^~~
/in/foo.c:35:20: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   for(i;*(a+i)!=0);i++)
                    ^
/in/foo.c:35:23: error: expected ';' before ')' token
   for(i;*(a+i)!=0);i++)
                       ^
/in/foo.c:35:23: error: expected statement before ')' token