Compilare: main.cpp: In function 'int main()': main.cpp:19:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses] in>>x+1; ~^~ main.cpp:39:67: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(s[imax][j]-s[imax][j-1]-s[imin-1][j]+s[imin-1][j-1]==imax-imin+1) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~ main.cpp:41:83: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(nri==1&&s[imax][j-1]-s[imax][j-2]-s[imin-1][j-1]+s[imin-1][j-2]==imax-imin+1) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~ main.cpp:14:18: warning: unused variable 'k' [-Wunused-variable] { int nr=0,nri=0,k=0; ^