towns.cpp: In function 'int chk(int)':
towns.cpp:30:24: warning: conversion from 'long unsigned int' to 'int' may change value [-Wconversion]
30 | int k = min(a.size(),b.size());
| ~~~^~~~~~~~~~~~~~~~~~~
towns.cpp:31:21: warning: declaration of 'i' shadows a global declaration [-Wshadow]
31 | for(int i=k;i<(int)a.size();i++) c.push_back(a[i]);
| ^
towns.cpp:11:20: note: shadowed declaration is here
11 | int N, A, B, C, R, i, j, cnt, rev[MN], pre[MN], suf[MN], dis[2][MN], ds[MN], mat[MN][MN];
| ^
towns.cpp:32:21: warning: declaration of 'i' shadows a global declaration [-Wshadow]
32 | for(int i=k;i<(int)b.size();i++) c.push_back(b[i]);
| ^
towns.cpp:11:20: note: shadowed declaration is here
11 | int N, A, B, C, R, i, j, cnt, rev[MN], pre[MN], suf[MN], dis[2][MN], ds[MN], mat[MN][MN];
| ^
towns.cpp:36:21: warning: declaration of 'i' shadows a global declaration [-Wshadow]
36 | for(int i=0;i<N;i++) mat[fnd(a[0].F)][i]=max(mat[fnd(a[0].F)][i],mat[fnd(b[0].F)][i]);
| ^
towns.cpp:11:20: note: shadowed declaration is here
11 | int N, A, B, C, R, i, j, cnt, rev[MN], pre[MN], suf[MN], dis[2][MN], ds[MN], mat[MN][MN];
| ^
towns.cpp:50:25: warning: declaration of 'i' shadows a global declaration [-Wshadow]
50 | for(int i=0;i<N;i++) mat[fnd(cand)][i]=max(mat[fnd(cand)][i],mat[fnd(v.F)][i]);
| ^
towns.cpp:11:20: note: shadowed declaration is here
11 | int N, A, B, C, R, i, j, cnt, rev[MN], pre[MN], suf[MN], dis[2][MN], ds[MN], mat[MN][MN];
| ^
towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:90:31: warning: conversion from 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
90 | pre[i] = vec[i].size()+pre[i-1];
| ~~~~~~~~~~~~~^~~~~~~~~
towns.cpp:92:44: warning: conversion from 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
92 | for(i=cnt;i>=1;i--) suf[i] = vec[i].size()+suf[i+1];
| ~~~~~~~~~~~~~^~~~~~~~~
towns.cpp:58:29: warning: unused parameter 'sub' [-Wunused-parameter]
58 | int hubDistance(int _N, int sub) {
| ~~~~^~~