#include <bits/stdc++.h> using namespace std; const int maxn = 1e5 + 100; #define fi first #define pdi pair < pair < double, double >, int > #define se second #define ll long long #define pii pair < int, int > const int MOD = 1e9 + 7; const ll inf = 1e18; vector < int > g[maxn]; pii edge[maxn]; int n, m, k, W[maxn], up[25][maxn],h[maxn]; void dfs(int u) { for (int v : g[u]) { if (v == up[0][u]) continue; h[v] = h[u] + 1; up[0][v] = u; for (int j = 1; j <= 20; j++) up[j][v] = up[j - 1][up[j - 1][v]]; dfs(v); } } int LCA(int u, int v) { if (h[u] < h[v]) swap(u, v); int k = h[u] - h[v]; for (int i = 20; i >= 0; i--) { if (k >> i & 1) u = up[i][u]; } if (u == v) return u; for (int i = 20; i >= 0; i--) { if (up[i][u] != up[i][v]) { u = up[i][u]; v = up[i][v]; } } return up[0][u]; } int dist(int u, int v) { return h[u] + h[v] - 2 * h[LCA(u, v)]; } signed main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); #define NAME "test" if (fopen(NAME".INP", "r")) { freopen(NAME".INP", "r",stdin); freopen(NAME".OUT", "w",stdout); } cin >> n >> m >> k; for (int i = 1; i < n; i++) { cin >> edge[i].fi >> edge[i].se; } for (int i = 1; i <= m; i++) { int id, val; cin >> id >> val; int u = edge[i].fi; int v = edge[i].se; W[id] += val; } int cst = 0; for (int i = 1; i < n; i++) { int u = edge[i].fi; int v = edge[i].se; int w = W[i]; cst = w; g[u].push_back(v); g[v].push_back(u); } dfs(1); for (int i = 1; i <= k; i++) { int u, v, x, y; cin >> u >> v >> x >> y; int d = dist(u, v); int f = d * cst; if (y >= f) { cout << x << '\n'; } else { int cnt = f / d * cst; d -= cnt; if (x >= d) cout << x - d << '\n'; else cout << -1 << '\n'; } } }

currencies.cpp: In function 'int main()':
currencies.cpp:56:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |         freopen(NAME".INP", "r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
currencies.cpp:57:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |         freopen(NAME".OUT", "w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~