/in/foo.cc: In function 'int main()':
/in/foo.cc:9:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(int i=1;i<=n;i++)
  ^~~
/in/foo.cc:11:4: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
    qsort(1,n);
    ^~~~~
/in/foo.cc:7:8: warning: unused variable 'i' [-Wunused-variable]
  int n,i;
        ^
/tmp/ccl8jpGd.o: In function `qosrt(int, int)':
foo.cc:(.text+0x6f): undefined reference to `qsort(int, int)'
foo.cc:(.text+0xa7): undefined reference to `qsort(int, int)'
/tmp/ccl8jpGd.o: In function `main':
foo.cc:(.text.startup+0x56): undefined reference to `qsort(int, int)'
collect2: error: ld returned 1 exit status