Compilare: user.cpp: In function ‘void getNeighbours(int, int)’: user.cpp:46:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < adjList[currVal].size() && adjList[currVal][j] != nextVal; j++); ^ user.cpp:47:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j == adjList[currVal].size()) { ^ user.cpp: In function ‘int main()’: user.cpp:93:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < adjList[currVal].size(); i++) { ^ user.cpp:56:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inFile, "r", stdin); ^ user.cpp:57:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(outFile, "w", stdout); ^ user.cpp:61:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n", &n, &m, &k); ^ user.cpp:63:21: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a[i]+1); ^ In file included from /usr/include/stdio.h:934:0, from /usr/include/c++/4.8/cstdio:42, from user.cpp:1: In function ‘char* gets(char*)’, inlined from ‘int main()’ at user.cpp:63:21: /usr/include/i386-linux-gnu/bits/stdio2.h:230:28: warning: call to ‘__gets_warn’ declared with attribute warning: please use fgets or getline instead, gets can't specify buffer size [enabled by default] return __gets_warn (__str); ^ /tmp/ccb7pRMr.o: In function `main': user.cpp:(.text.startup+0x8d): warning: the `gets' function is dangerous and should not be used.