#include <bits/stdc++.h> #define taskname "" using namespace std; using ld = long double; using ull = unsigned long long; using ll = long long; const char el = '\n'; const char sp = ' '; const ll inf = 1e18; const int maxN = 50005; const int maxK = 5; int K, N, M, O; ll dp[maxN][31][maxK][maxK]; struct Tmat { ll val[maxK][maxK]; Tmat() { for (int i = 0; i < maxK; ++i) for (int j = 0; j < maxK; ++j) val[i][j] = inf; } }; Tmat combine(int in1, int in2) { Tmat cur; for (int i = 0; i < K; ++i) cur.val[i][i] = 0; int dif = in2 - in1; while (dif > 0) { int j = 31 - __builtin_clz(dif); Tmat nxt; for (int i = 0; i < K; ++i) { for (int k = 0; k < K; ++k) { if (cur.val[i][k] >= inf) continue; for (int l = 0; l < K; ++l) { nxt.val[i][l] = min(nxt.val[i][l], cur.val[i][k] + dp[in1][j][k][l]); } } } dif -= (1 << j); in1 += (1 << j); cur = nxt; } return cur; } int main () { ios_base::sync_with_stdio(0); cin.tie(0); if (fopen(taskname ".inp", "r")) { freopen(taskname ".inp", "r", stdin); freopen(taskname ".out", "w", stdout); } if (!(cin >> K >> N >> M >> O)) return 0; N++; while (N % K != K - 1) N++; for (int j = 0; j <= 30; ++j) { for (int i = 0; i < N / K; ++i) { for (int x = 0; x < K; ++x) for (int y = 0; y < K; ++y) dp[i][j][x][y] = inf; } } while (M--) { int u, v; ll w; cin >> u >> v >> w; dp[u / K][0][u % K][v % K] = min(dp[u / K][0][u % K][v % K], w); } for (int j = 1; j <= 30; ++j) { for (int i = 0; i < N / K; ++i) { if (i + (1 << (j - 1)) >= N / K) continue; for (int x = 0; x < K; ++x) { for (int z = 0; z < K; ++z) { if (dp[i][j - 1][x][z] >= inf) continue; for (int y = 0; y < K; ++y) { dp[i][j][x][y] = min(dp[i][j][x][y], dp[i][j - 1][x][z] + dp[i + (1 << (j - 1))][j - 1][z][y]); } } } } } while (O--) { int u, v; cin >> u >> v; if (u / K >= v / K) { cout << -1 << el; continue; } Tmat res = combine(u / K, v / K); ll ans = res.val[u % K][v % K]; if (ans >= inf) cout << -1 << el; else cout << ans << el; } return 0; }

toll.cpp: In function 'int main()':
toll.cpp:60:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         freopen(taskname ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
toll.cpp:61:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |         freopen(taskname ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~