Compilare: user.cpp: In function ‘int main()’: user.cpp:4:639: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std; int a[N][N],sol[N][N],x,y,i,j,nr,n,MAX=-1,xf,yf; int dx[]= {-1,1,0,0};int dy[]= {0,0,-1,1};int fill ( int x, int y){int Max=0;for(int t=0; t<=3; ++t) if(a[x][y]<a[x+dx[t]][y+dy[t]] && x+dx[t]>0 && x+dx[t]<=n && y+dy[t]>0 && y+dy[t]<=n){if(sol[x+dx[t]][y+dy[t]]!=-1) Max=max(Max,sol[x+dx[t]][y+dy[t]]); else Max=max(fill(x+dx[t],y+dy[t]),Max);}sol[x][y]=Max+1; return Max+1;}void drum(int x, int y, int nr){printf("%d %d\n",x,y);for(int t=0; t<=3; ++t) if(sol[x+dx[t]][y+dy[t]]==nr-1 && x+dx[t]>0 && x+dx[t]<=n && y+dy[t]>0 && y+dy[t]<=n) { drum(x+dx[t],y+dy[t],nr-1); break;}}int main(){ freopen("alpin.in","r",stdin); freopen("alpin.out","w",stdout);scanf("%d",&n);for(i=1; i<=n; ++i) for(j=1; j<=n; ++j){ scanf("%d",&a[i][j]); sol[i][j]=-1;}for(i=1; i<=n; ++i) for(j=1; j<=n; ++j) if(sol[i][j]==-1){ sol[i][j]=fill(i,j); if(MAX<sol[i][j]) {MAX=sol[i][j]; xf=i; yf=j;}} printf("%d\n",MAX); drum(xf,yf,MAX);} ^ user.cpp:4:672: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std; int a[N][N],sol[N][N],x,y,i,j,nr,n,MAX=-1,xf,yf; int dx[]= {-1,1,0,0};int dy[]= {0,0,-1,1};int fill ( int x, int y){int Max=0;for(int t=0; t<=3; ++t) if(a[x][y]<a[x+dx[t]][y+dy[t]] && x+dx[t]>0 && x+dx[t]<=n && y+dy[t]>0 && y+dy[t]<=n){if(sol[x+dx[t]][y+dy[t]]!=-1) Max=max(Max,sol[x+dx[t]][y+dy[t]]); else Max=max(fill(x+dx[t],y+dy[t]),Max);}sol[x][y]=Max+1; return Max+1;}void drum(int x, int y, int nr){printf("%d %d\n",x,y);for(int t=0; t<=3; ++t) if(sol[x+dx[t]][y+dy[t]]==nr-1 && x+dx[t]>0 && x+dx[t]<=n && y+dy[t]>0 && y+dy[t]<=n) { drum(x+dx[t],y+dy[t],nr-1); break;}}int main(){ freopen("alpin.in","r",stdin); freopen("alpin.out","w",stdout);scanf("%d",&n);for(i=1; i<=n; ++i) for(j=1; j<=n; ++j){ scanf("%d",&a[i][j]); sol[i][j]=-1;}for(i=1; i<=n; ++i) for(j=1; j<=n; ++j) if(sol[i][j]==-1){ sol[i][j]=fill(i,j); if(MAX<sol[i][j]) {MAX=sol[i][j]; xf=i; yf=j;}} printf("%d\n",MAX); drum(xf,yf,MAX);} ^ user.cpp:4:687: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std; int a[N][N],sol[N][N],x,y,i,j,nr,n,MAX=-1,xf,yf; int dx[]= {-1,1,0,0};int dy[]= {0,0,-1,1};int fill ( int x, int y){int Max=0;for(int t=0; t<=3; ++t) if(a[x][y]<a[x+dx[t]][y+dy[t]] && x+dx[t]>0 && x+dx[t]<=n && y+dy[t]>0 && y+dy[t]<=n){if(sol[x+dx[t]][y+dy[t]]!=-1) Max=max(Max,sol[x+dx[t]][y+dy[t]]); else Max=max(fill(x+dx[t],y+dy[t]),Max);}sol[x][y]=Max+1; return Max+1;}void drum(int x, int y, int nr){printf("%d %d\n",x,y);for(int t=0; t<=3; ++t) if(sol[x+dx[t]][y+dy[t]]==nr-1 && x+dx[t]>0 && x+dx[t]<=n && y+dy[t]>0 && y+dy[t]<=n) { drum(x+dx[t],y+dy[t],nr-1); break;}}int main(){ freopen("alpin.in","r",stdin); freopen("alpin.out","w",stdout);scanf("%d",&n);for(i=1; i<=n; ++i) for(j=1; j<=n; ++j){ scanf("%d",&a[i][j]); sol[i][j]=-1;}for(i=1; i<=n; ++i) for(j=1; j<=n; ++j) if(sol[i][j]==-1){ sol[i][j]=fill(i,j); if(MAX<sol[i][j]) {MAX=sol[i][j]; xf=i; yf=j;}} printf("%d\n",MAX); drum(xf,yf,MAX);} ^ user.cpp:4:749: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std; int a[N][N],sol[N][N],x,y,i,j,nr,n,MAX=-1,xf,yf; int dx[]= {-1,1,0,0};int dy[]= {0,0,-1,1};int fill ( int x, int y){int Max=0;for(int t=0; t<=3; ++t) if(a[x][y]<a[x+dx[t]][y+dy[t]] && x+dx[t]>0 && x+dx[t]<=n && y+dy[t]>0 && y+dy[t]<=n){if(sol[x+dx[t]][y+dy[t]]!=-1) Max=max(Max,sol[x+dx[t]][y+dy[t]]); else Max=max(fill(x+dx[t],y+dy[t]),Max);}sol[x][y]=Max+1; return Max+1;}void drum(int x, int y, int nr){printf("%d %d\n",x,y);for(int t=0; t<=3; ++t) if(sol[x+dx[t]][y+dy[t]]==nr-1 && x+dx[t]>0 && x+dx[t]<=n && y+dy[t]>0 && y+dy[t]<=n) { drum(x+dx[t],y+dy[t],nr-1); break;}}int main(){ freopen("alpin.in","r",stdin); freopen("alpin.out","w",stdout);scanf("%d",&n);for(i=1; i<=n; ++i) for(j=1; j<=n; ++j){ scanf("%d",&a[i][j]); sol[i][j]=-1;}for(i=1; i<=n; ++i) for(j=1; j<=n; ++j) if(sol[i][j]==-1){ sol[i][j]=fill(i,j); if(MAX<sol[i][j]) {MAX=sol[i][j]; xf=i; yf=j;}} printf("%d\n",MAX); drum(xf,yf,MAX);} ^