Compilare: user.cpp: In function ‘int main()’: user.cpp:29:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&N); ^ user.cpp:30:74: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1;i<=N;i++)for(int j=1;j<=N;j++){fscanf(f,"%d",&cost[i][j]);if(!cost[i][j])cost[i][j]=1<<24;} ^