triangle.cpp: In function 'void solve()':
triangle.cpp:7:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
7 | freopen ("triangles.in","r",stdin);
| ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
triangle.cpp:8:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
8 | freopen ("triangles.out","w",stdout);
| ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~