Compilare: main.cpp: In function 'int main()': main.cpp:76:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < slopes.size(); i++) ~~^~~~~~~~~~~~~~~ main.cpp:55:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trapez.in","r",stdin); ^ main.cpp:56:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trapez.out","w",stdout); ^ main.cpp:58:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:61:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&tempx,&tempy); ^