#include <bits/stdc++.h> #define ll long long #define fors(u, n, s) for(ll u = (s); u < (n); u++) #define foru(u, n) fors(u, n, 0) #define f first #define s second #define vec vector #define pb push_back #define ir(a, b, x) (((a) <= (x)) && ((x) <= (b))) using namespace std; const int N = 110; const int M = 210; int n, m; ll p[N]; vec<pair<int, ll>> edges[N]; const int P = 1e9; const int K = 2e5; const int L = (P/K)+100; bool left_reachable[N][K]; void reset_left(){ foru(i, n) foru(j, K) left_reachable[i][j] = false; } void left_dfs(int node, ll val) { if(val >= K) return; if(left_reachable[node][val]) return; if(val > p[node]) return; left_reachable[node][val] = true; for(auto i : edges[node]) { ll next_val = val*i.s; if(next_val >= K) continue; left_dfs(i.f, next_val); } } ll biggest[N][K]; void reset_biggest(){ foru(i, n) foru(j, K) biggest[i][j] = -1; } ll find_biggest(int node, ll max_mult) { // cout << "CALLED BIGGEST " << node << " " << max_mult << endl; if(max_mult == 0) return 0; max_mult = min(max_mult, K-1LL); if(biggest[node][max_mult] != -1) return biggest[node][max_mult]; if(left_reachable[node][max_mult]) { // cout << "BIGGEST VAL ON NODE " << node << " SMALLER THAN " << max_mult << " IS " << max_mult << endl; biggest[node][max_mult] = max_mult; return max_mult; } biggest[node][max_mult] = find_biggest(node, max_mult-1); // cout << "BIGGEST VAL ON NODE " << node << " SMALLER THAN " << max_mult << " IS " << biggest[node][max_mult] << endl; return biggest[node][max_mult]; } ll right_limit[N][L]; void reset_right(){ foru(i, n) foru(j, L) right_limit[i][j] = -1; } ll limit_in_path[N][N]; void calculate_limit_in_path(){ foru(i, n) foru(j, n) limit_in_path[i][j] = 0; foru(i, n) limit_in_path[i][i] = p[i]; foru(i, n) for(auto e : edges[i]) { int j = e.f; ll w = e.s; if(w != 1) continue; limit_in_path[i][j] = min(p[i], p[j]); } foru(i, n) { foru(a, n) foru(b, n) { limit_in_path[a][b] = max( limit_in_path[a][b], min(limit_in_path[a][i], limit_in_path[i][b]) ); } } // cout << "DEBUG: " << endl; // foru(i, n) { // foru(j, n) { // cout << limit_in_path[i][j] << " "; // } // cout << endl; // } } ll get_right_limit(int node, ll val){ // cout << "CALLED " << node << " " << val << endl; if(limit_in_path[node][n-1] != 0 && val == 1) return limit_in_path[node][n-1]; if(val == 0) return 0; if(right_limit[node][val] != -1) return right_limit[node][val]; ll limit = 0; foru(i, n) { ll base_limit = limit_in_path[node][i]; if(base_limit == 0) continue; for(auto e : edges[i]) { ll mult = e.s; int next_node = e.f; if(mult == 1) continue; if(val%mult != 0) continue; ll next_val = val/mult; if(next_val >= L) continue; ll next_limit = get_right_limit(next_node, next_val); next_limit /= mult; next_limit = min(next_limit, base_limit); limit = max(limit, next_limit); } } right_limit[node][val] = limit; return limit; } void solve(){ cin >> n >> m; foru(i, n) cin >> p[i]; foru(i, n) edges[i] = {}; foru(_i, m){ int a, b, w; cin >> a >> b >> w; a--; b--; edges[a].pb({b, w}); } reset_left(); left_dfs(0, 1); ll ans = -1; foru(i, K) if(left_reachable[n-1][i]) ans = i; reset_right(); reset_biggest(); calculate_limit_in_path(); foru(a, n) for(auto e : edges[a]) { int b = e.f; ll mult = e.s; // cout << "CONCIDERING MIDDLE EDGE " << a << " " << b << " WITH MULT " << mult << endl; fors(i, L, 1) { ll limit = get_right_limit(b, i); if(limit == 0) continue; // cout << endl; // cout << " ASSUMING RIGHT MULT IS " << i << endl; // cout << " RIGHT LIMIT " << limit << endl; limit /= mult; limit = min(limit, p[a]); // cout << " LIMIT BEFORE EDGE " << limit << endl; if(limit == 0) continue; ll left_mult = find_biggest(a, limit); // cout << " BIGGEST LEFT_MULT " << left_mult << endl; if(left_mult == 0) continue; ans = max(ans, left_mult*i*mult); } } cout << ans << endl; } int main() { cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0); int t; cin >> t; foru(_i, t) solve(); return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 | #include <bits/stdc++.h> #define ll long long #define fors(u, n, s) for(ll u = (s); u < (n); u++) #define foru(u, n) fors(u, n, 0) #define f first #define s second #define vec vector #define pb push_back #define ir(a, b, x) (((a) <= (x)) && ((x) <= (b))) using namespace std; const int N = 110; const int M = 210; int n, m; ll p[N]; vec<pair<int, ll>> edges[N]; const int P = 1e9; const int K = 2e5; const int L = (P/K)+100; bool left_reachable[N][K]; void reset_left(){ foru(i, n) foru(j, K) left_reachable[i][j] = false; } void left_dfs(int node, ll val) { if(val >= K) return; if(left_reachable[node][val]) return; if(val > p[node]) return; left_reachable[node][val] = true; for(auto i : edges[node]) { ll next_val = val*i.s; if(next_val >= K) continue; left_dfs(i.f, next_val); } } ll biggest[N][K]; void reset_biggest(){ foru(i, n) foru(j, K) biggest[i][j] = -1; } ll find_biggest(int node, ll max_mult) { // cout << "CALLED BIGGEST " << node << " " << max_mult << endl; if(max_mult == 0) return 0; max_mult = min(max_mult, K-1LL); if(biggest[node][max_mult] != -1) return biggest[node][max_mult]; if(left_reachable[node][max_mult]) { // cout << "BIGGEST VAL ON NODE " << node << " SMALLER THAN " << max_mult << " IS " << max_mult << endl; biggest[node][max_mult] = max_mult; return max_mult; } biggest[node][max_mult] = find_biggest(node, max_mult-1); // cout << "BIGGEST VAL ON NODE " << node << " SMALLER THAN " << max_mult << " IS " << biggest[node][max_mult] << endl; return biggest[node][max_mult]; } ll right_limit[N][L]; void reset_right(){ foru(i, n) foru(j, L) right_limit[i][j] = -1; } ll limit_in_path[N][N]; void calculate_limit_in_path(){ foru(i, n) foru(j, n) limit_in_path[i][j] = 0; foru(i, n) limit_in_path[i][i] = p[i]; foru(i, n) for(auto e : edges[i]) { int j = e.f; ll w = e.s; if(w != 1) continue; limit_in_path[i][j] = min(p[i], p[j]); } foru(i, n) { foru(a, n) foru(b, n) { limit_in_path[a][b] = max( limit_in_path[a][b], min(limit_in_path[a][i], limit_in_path[i][b]) ); } } // cout << "DEBUG: " << endl; // foru(i, n) { // foru(j, n) { // cout << limit_in_path[i][j] << " "; // } // cout << endl; // } } ll get_right_limit(int node, ll val){ // cout << "CALLED " << node << " " << val << endl; if(limit_in_path[node][n-1] != 0 && val == 1) return limit_in_path[node][n-1]; if(val == 0) return 0; if(right_limit[node][val] != -1) return right_limit[node][val]; ll limit = 0; foru(i, n) { ll base_limit = limit_in_path[node][i]; if(base_limit == 0) continue; for(auto e : edges[i]) { ll mult = e.s; int next_node = e.f; if(mult == 1) continue; if(val%mult != 0) continue; ll next_val = val/mult; if(next_val >= L) continue; ll next_limit = get_right_limit(next_node, next_val); next_limit /= mult; next_limit = min(next_limit, base_limit); limit = max(limit, next_limit); } } right_limit[node][val] = limit; return limit; } void solve(){ cin >> n >> m; foru(i, n) cin >> p[i]; foru(i, n) edges[i] = {}; foru(_i, m){ int a, b, w; cin >> a >> b >> w; a--; b--; edges[a].pb({b, w}); } reset_left(); left_dfs(0, 1); ll ans = -1; foru(i, K) if(left_reachable[n-1][i]) ans = i; reset_right(); reset_biggest(); calculate_limit_in_path(); foru(a, n) for(auto e : edges[a]) { int b = e.f; ll mult = e.s; // cout << "CONCIDERING MIDDLE EDGE " << a << " " << b << " WITH MULT " << mult << endl; fors(i, L, 1) { ll limit = get_right_limit(b, i); if(limit == 0) continue; // cout << endl; // cout << " ASSUMING RIGHT MULT IS " << i << endl; // cout << " RIGHT LIMIT " << limit << endl; limit /= mult; limit = min(limit, p[a]); // cout << " LIMIT BEFORE EDGE " << limit << endl; if(limit == 0) continue; ll left_mult = find_biggest(a, limit); // cout << " BIGGEST LEFT_MULT " << left_mult << endl; if(left_mult == 0) continue; ans = max(ans, left_mult*i*mult); } } cout << ans << endl; } int main() { cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0); int t; cin >> t; foru(_i, t) solve(); return 0; } |