friend.cpp: In function 'void dfs(int)':
friend.cpp:13:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < x[pos].size(); i++) dfs(x[pos][i]);
~~^~~~~~~~~~~~~~~
friend.cpp:15:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < x[pos].size(); i++) dp[i][0] += max(dp[x[pos][i]][0], dp[x[pos][i]][1]);
~~^~~~~~~~~~~~~~~
friend.cpp:16:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < x[pos].size(); i++) dp[i][1] += dp[x[pos][i]][0];
~~^~~~~~~~~~~~~~~
friend.cpp: In function 'int findSample(int, int*, int*, int*)':
friend.cpp:39:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int j = 0; j < vec.size(); j++) {
~~^~~~~~~~~~~~
friend.cpp:40:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int k = j + 1; k < vec.size(); k++) {
~~^~~~~~~~~~~~
friend.cpp:45:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
int bit = 0; for (int j = 0; j < vec.size(); j++) bit += confidence[vec[j]];
~~^~~~~~~~~~~~