Compilare: user.cpp: In function ‘int main()’: user.cpp:29:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0;k<strlen(x);++k) ^ user.cpp:37:40: warning: narrowing conversion of ‘a[xf][yf]’ from ‘long unsigned int’ to ‘int’ inside { } [-Wnarrowing] q.push_back((coord) {xf,yf,a[xf][yf]}); ^ user.cpp:51:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if((a[xx][yy]<min1||min1==0)&&a[xx][yy]>0) ^ user.cpp:64:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(q.size()==nre||!nre) ^ user.cpp:17:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("traseu2.in","r",stdin); ^ user.cpp:18:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("traseu2.out","w",stdout); ^ user.cpp:19:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:23:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",x); ^