Compilare: user.cpp: In function ‘int main()’: user.cpp:74:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=1;k<v2[vaz[i][j]].size();k++) ^ user.cpp:76:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v2[vaz[i][j]].size()-1<kk) {vaz3[vaz[i][j]]=1;q1.push(vaz[i][j]);} ^ user.cpp:83:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<v2[x].size();i++) ^ user.cpp:101:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<v2[x].size();i++) ^ user.cpp:40:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zone2.in","r",stdin); ^ user.cpp:41:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zone2.out","w",stdout); ^ user.cpp:43:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d\n",&n,&m,&kk); ^ user.cpp:44:39: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1;i<=n;i++) gets(v[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:44:39: /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/ccRApbm0.o: In function `main': user.cpp:(.text.startup+0x8f): warning: the `gets' function is dangerous and should not be used.