Compilare: user.cpp: In function ‘void Up_and_Down()’: user.cpp:67:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, sum, p1, p2, k; ^ user.cpp: In function ‘void Read()’: user.cpp:23:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &op); ^ user.cpp:24:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &m, &n, &k1, &k2); ^ user.cpp:27:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &A[i][j]); ^