Compilare: user.cpp: In function ‘void Read()’: user.cpp:70:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 1; i <= M; i++ ) ^ user.cpp:65:18: warning: unused variable ‘j’ [-Wunused-variable] int i, x, y, j; ^ user.cpp: In function ‘void Solve()’: user.cpp:96:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 2; i <= N; i++ ) ^ user.cpp:99:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( j = 1; j <= M; j++ ) ^ user.cpp:86:9: warning: unused variable ‘x’ [-Wunused-variable] int x, y; ^ user.cpp:86:12: warning: unused variable ‘y’ [-Wunused-variable] int x, y; ^