Compilare: user.cpp: In function ‘int case2()’: user.cpp:65:29: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] { if(index_up<=k1 && Mat[up][index_up]<=Mat[down][index_down] || index_down>k2) ^ user.cpp:71:29: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(index_up<=k1 && Mat[up][index_up]<=Mat[down][index_down] || index_down>k2) ^ user.cpp: In function ‘int main()’: user.cpp:82:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen(IN, "r", stdin); ^ user.cpp:83:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(OUT, "w", stdout); ^ user.cpp:84:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d",&Case,&N,&M,&k1,&k2); ^ user.cpp:86:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int j=1;j<=M;++j) scanf("%d",&Mat[j][i]); ^