Compilare: user.cpp: In function ‘int main()’: user.cpp:8:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("piese2.in", "r", stdin); ^ user.cpp:9:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("piese2.out", "w", stdout); ^ user.cpp:10:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(scanf("%d", &t); t; --t) { ^ user.cpp:11:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(rs = 0, scanf("%d %d", &n, &k); k; --k) scanf("%d %d", &x, &y), rs += abs(x - y) - 1; ^ user.cpp:11:93: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(rs = 0, scanf("%d %d", &n, &k); k; --k) scanf("%d %d", &x, &y), rs += abs(x - y) - 1; ^