Compilare: user.cpp: In function ‘int main()’: user.cpp:4:562: 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],s[N][N],x,y,i,j,nr,n,Z=-1,xf,yf,dx[]={-1,1,0,0},dy[]={0,0,-1,1};int F(int x,int y){int Z=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(s[x+dx[t]][y+dy[t]]!=-1) Z=max(Z,s[x+dx[t]][y+dy[t]]);else Z=max(F(x+dx[t],y+dy[t]),Z);}s[x][y]=Z+1;return Z+1;}void drum(int x,int y,int nr){printf("%d %d\n",x,y);for(int t=0;t<=3;++t)if(s[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]),s[i][j]=-1;for(i=1;i<=n;++i)for(j=1;j<=n;++j)if(s[i][j]==-1){s[i][j]=F(i,j);if(Z<s[i][j]){Z=s[i][j];xf=i;yf=j;}}printf("%d\n",Z);drum(xf,yf,Z);} ^ user.cpp:4:594: 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],s[N][N],x,y,i,j,nr,n,Z=-1,xf,yf,dx[]={-1,1,0,0},dy[]={0,0,-1,1};int F(int x,int y){int Z=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(s[x+dx[t]][y+dy[t]]!=-1) Z=max(Z,s[x+dx[t]][y+dy[t]]);else Z=max(F(x+dx[t],y+dy[t]),Z);}s[x][y]=Z+1;return Z+1;}void drum(int x,int y,int nr){printf("%d %d\n",x,y);for(int t=0;t<=3;++t)if(s[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]),s[i][j]=-1;for(i=1;i<=n;++i)for(j=1;j<=n;++j)if(s[i][j]==-1){s[i][j]=F(i,j);if(Z<s[i][j]){Z=s[i][j];xf=i;yf=j;}}printf("%d\n",Z);drum(xf,yf,Z);} ^ user.cpp:4:609: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std;int a[N][N],s[N][N],x,y,i,j,nr,n,Z=-1,xf,yf,dx[]={-1,1,0,0},dy[]={0,0,-1,1};int F(int x,int y){int Z=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(s[x+dx[t]][y+dy[t]]!=-1) Z=max(Z,s[x+dx[t]][y+dy[t]]);else Z=max(F(x+dx[t],y+dy[t]),Z);}s[x][y]=Z+1;return Z+1;}void drum(int x,int y,int nr){printf("%d %d\n",x,y);for(int t=0;t<=3;++t)if(s[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]),s[i][j]=-1;for(i=1;i<=n;++i)for(j=1;j<=n;++j)if(s[i][j]==-1){s[i][j]=F(i,j);if(Z<s[i][j]){Z=s[i][j];xf=i;yf=j;}}printf("%d\n",Z);drum(xf,yf,Z);} ^ user.cpp:4:675: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std;int a[N][N],s[N][N],x,y,i,j,nr,n,Z=-1,xf,yf,dx[]={-1,1,0,0},dy[]={0,0,-1,1};int F(int x,int y){int Z=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(s[x+dx[t]][y+dy[t]]!=-1) Z=max(Z,s[x+dx[t]][y+dy[t]]);else Z=max(F(x+dx[t],y+dy[t]),Z);}s[x][y]=Z+1;return Z+1;}void drum(int x,int y,int nr){printf("%d %d\n",x,y);for(int t=0;t<=3;++t)if(s[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]),s[i][j]=-1;for(i=1;i<=n;++i)for(j=1;j<=n;++j)if(s[i][j]==-1){s[i][j]=F(i,j);if(Z<s[i][j]){Z=s[i][j];xf=i;yf=j;}}printf("%d\n",Z);drum(xf,yf,Z);} ^