Compilare: main.cpp: In function 'void write()': main.cpp:143:9: warning: unused variable 'i' [-Wunused-variable] int i, j; ^ main.cpp:143:12: warning: unused variable 'j' [-Wunused-variable] int i, j; ^ main.cpp: In function 'void read()': main.cpp:11:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("summax.in", "r", stdin); ^ main.cpp:12:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ main.cpp:13:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &l, &r); ^ main.cpp:21:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^ main.cpp: In function 'void write()': main.cpp:144:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("summax.out", "w", stdout); ^