Compilare: main.cpp: In function 'int main()': main.cpp:2:89: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] int f,r,m,n,i,j,k,l,t=-1001,y,e,s,b[1001],c[1001];int main(){freopen("joc.in","r",stdin);freopen("joc.out","w",stdout),scanf("%d%d",&n,&m);for(i=1;i<=n;i++){ for(j=1;j<=m;j++){scanf("%d",&r),y=b[j]>c[j-1]?b[j]:c[j-1],e=r-y,s=b[j]=c[j]=y>e?y:e;if(i+j==2){b[j]=c[j]=s=f=r;}else if(i+j==3){b[j]=c[j]=s=s>(r-f)?s:(r-f);}if(s>t){t=s,k=i,l=j;}}}printf("%d %d %d",t,k,l);return 0;} ^ main.cpp:2:139: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] int f,r,m,n,i,j,k,l,t=-1001,y,e,s,b[1001],c[1001];int main(){freopen("joc.in","r",stdin);freopen("joc.out","w",stdout),scanf("%d%d",&n,&m);for(i=1;i<=n;i++){ for(j=1;j<=m;j++){scanf("%d",&r),y=b[j]>c[j-1]?b[j]:c[j-1],e=r-y,s=b[j]=c[j]=y>e?y:e;if(i+j==2){b[j]=c[j]=s=f=r;}else if(i+j==3){b[j]=c[j]=s=s>(r-f)?s:(r-f);}if(s>t){t=s,k=i,l=j;}}}printf("%d %d %d",t,k,l);return 0;} ^ main.cpp:2:139: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:2:243: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] int f,r,m,n,i,j,k,l,t=-1001,y,e,s,b[1001],c[1001];int main(){freopen("joc.in","r",stdin);freopen("joc.out","w",stdout),scanf("%d%d",&n,&m);for(i=1;i<=n;i++){ for(j=1;j<=m;j++){scanf("%d",&r),y=b[j]>c[j-1]?b[j]:c[j-1],e=r-y,s=b[j]=c[j]=y>e?y:e;if(i+j==2){b[j]=c[j]=s=f=r;}else if(i+j==3){b[j]=c[j]=s=s>(r-f)?s:(r-f);}if(s>t){t=s,k=i,l=j;}}}printf("%d %d %d",t,k,l);return 0;} ^