Compilare: main.cpp: In function 'int main()': main.cpp:11:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation] for(int i = 4; i <= b; i = i + 2) ^~~ main.cpp:13:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for' for (int i = 3; i * i <= b; i = i + 2) ^~~ main.cpp:6:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("difprim.in","r",stdin); ^ main.cpp:7:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("difprim.out","w",stdout); ^ main.cpp:9:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^ main.cpp:25:35: warning: 'n1' may be used uninitialized in this function [-Wmaybe-uninitialized] for (int i = (n1 + 1) + 1 - ((n1 + 1) % 2); i <= b; i = i + 2) { ~~~~^~~~