Compilare: user.cpp: In function ‘int case2()’: user.cpp:112:33: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if ( index_up <= k1 && Mat[up][index_up] <= Mat[down][index_down] || index_down > k2 ) { ^ user.cpp:125:33: 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:157:28: 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:158:30: 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:160:49: 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:164:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &Mat[j][i]); ^