gondola.cpp: In function 'int replacement(int, int*, int*)':
gondola.cpp:60:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<p.size();i++){
~^~~~~~~~~
gondola.cpp:38:16: warning: 'val' may be used uninitialized in this function [-Wmaybe-uninitialized]
int ind=-1,val;
^~~
/tmp/ccYeg43g.o: In function `main':
grader.cpp:(.text.startup+0xc3): undefined reference to `countReplacement'
grader.cpp:(.text.startup+0xe2): undefined reference to `valid'
grader.cpp:(.text.startup+0x106): undefined reference to `replacement'
collect2: error: ld returned 1 exit status