triangle.cpp:46:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
main()
^
triangle.cpp: In function 'int main()':
triangle.cpp:69:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0; i < xy.size(); i++)
~~^~~~~~~~~~~
triangle.cpp:48:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen("triangles.in" , "r" , stdin);
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
triangle.cpp:49:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen("triangles.out" , "w" , stdout);
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
triangle.cpp:58:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d" , &a , &b);
~~~~~^~~~~~~~~~~~~~~~~~