merchant.cpp: In function 'int main()':
merchant.cpp:31:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<adj[0].size();i++) {
~^~~~~~~~~~~~~~
merchant.cpp:37:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int k=0;k<adj[j].size();k++) {
~^~~~~~~~~~~~~~
merchant.cpp:13:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d %d",&n,&m,&k);
~~~~~^~~~~~~~~~~~~~~~~~~~~
merchant.cpp:17:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d",&buy[i][j],&sell[i][j]);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:22:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d %d",&u,&v,&w);
~~~~~^~~~~~~~~~~~~~~~~~~~~