pipes.cpp: In function 'void go(int)':
pipes.cpp:28:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0; i < G[v].size(); ++ i)
~~^~~~~~~~~~~~~
pipes.cpp: In function 'void dfs(int)':
pipes.cpp:41:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0; i < G[v].size(); ++ i)
~~^~~~~~~~~~~~~
pipes.cpp: In function 'int main()':
pipes.cpp:60:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &n, &m);
~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:67:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &x, &y);
~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:77:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &n, &m);
~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:80:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &x, &y);
~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:91:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &n, &m);
~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:96:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &x, &y);
~~~~~^~~~~~~~~~~~~~~~~