desen.cpp: In function 'int main()': desen.cpp:25: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result desen.cpp:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result desen.cpp: In function 'double kruskal(int)': desen.cpp:61: warning: comparison between signed and unsigned integer expressions