Compilare: main.cpp: In function 'int main()': main.cpp:9:11: warning: unused variable 'j' [-Wunused-variable] int i,j,n,k, t, nn; ^ main.cpp:9:15: warning: unused variable 'k' [-Wunused-variable] int i,j,n,k, t, nn; ^ main.cpp:9:21: warning: unused variable 'nn' [-Wunused-variable] int i,j,n,k, t, nn; ^~ main.cpp:7:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("quadratum.in", "r", stdin); ^ main.cpp:8:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("quadratum.out", "w", stdout); ^ main.cpp:11:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ main.cpp:15:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^