View Compilation Error

0_0_18013077_19205.cpp:74:3: error: stray '\' in program
   printf("%d %d %.1lf\n", original, now, 1.0*original\now);
   ^
0_0_18013077_19205.cpp: In function 'int main()':
0_0_18013077_19205.cpp:61:42: error: 'strcmp' was not declared in this scope
  while(scanf("%s", str)&&strcmp(str,"END")!=0){
                                          ^
0_0_18013077_19205.cpp:63:19: error: 'strlen' was not declared in this scope
   len = strlen(str);
                   ^
0_0_18013077_19205.cpp:74:55: error: expected ')' before 'now'
   printf("%d %d %.1lf\n", original, now, 1.0*original\now);
                                                       ^