citymapping.cpp: In function 'void f(std::vector<int>)':
citymapping.cpp:26:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=0; i<v.size(); i++) d.push_back(b[i] - c[i]);
~^~~~~~~~~
citymapping.cpp:29:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=0; i<v.size(); i++) ind.push_back(i);
~^~~~~~~~~
citymapping.cpp:35:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=0; i<b.size(); i++) tb.push_back(b[ind[i]]);
~^~~~~~~~~
citymapping.cpp:37:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=0; i<d.size(); i++) td.push_back(d[ind[i]]);
~^~~~~~~~~
citymapping.cpp:39:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=0; i<v.size(); i++) tv.push_back(v[ind[i]]);
~^~~~~~~~~
citymapping.cpp:42:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=0; i<v.size(); ) {
~^~~~~~~~~
citymapping.cpp:45:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
while (i+1<v.size() and d[i] == d[i+1]) {
~~~^~~~~~~~~
citymapping.cpp:49:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if (i < v.size()) {
~~^~~~~~~~~~
citymapping.cpp: In function 'void find_roads(int, int, int*, int*, int*)':
citymapping.cpp:76:13: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
swap(v[k-1], v[n-1]);
~^~