Submission #132265

#	Time	Username	Problem	Language	Result	Execution time	Memory
132265		gs14004	Wild Boar (JOI18_wild_boar)	C++17	62 / 100	18124 ms	537464 KiB

wild_boar

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2005;
const int MAXL = 100005;
using lint = long long;
using pi = pair<lint, int>;

struct edg{
	int pos, idx, cost;
};

int n, m, q, l;
vector<edg> gph[MAXN];
lint dist[MAXN * 2][MAXN * 2];

struct path_info{
	int midl, midr;
	lint cost;
	bool operator<(const path_info &p)const{
		return cost < p.cost;
	}
};

vector<path_info> plist[MAXN][MAXN];
int ed[MAXN * 2], cost[MAXN * 2];

void preprocess(){
	for(int i=0; i<m; i++){
		int s, e, x; scanf("%d %d %d",&s,&e,&x);
		ed[2 * i] = e; ed[2 * i + 1] = s;
		cost[2 * i] = cost[2 * i + 1] = x;
		gph[s].push_back({e, i*2, x});
		gph[e].push_back({s, i*2+1, x});
	}
	memset(dist, 0x3f, sizeof(dist));
	for(int i=0; i<2*m; i++){
		dist[i][i] = cost[i];
		priority_queue<pi, vector<pi>, greater<pi> > pq;
		pq.emplace(cost[i], i);
		int vis[MAXN] = {};
		while(!pq.empty()){
			auto x = pq.top(); pq.pop();
			if(dist[i][x.second] != x.first) continue;
			vis[ed[x.second]]++;
			if(vis[ed[x.second]] > 2) continue;
			for(auto &j : gph[ed[x.second]]){
				if((j.idx ^ x.second) == 1) continue;
				if(dist[i][j.idx] > x.first + j.cost){
					dist[i][j.idx] = x.first + j.cost;
					pq.emplace(dist[i][j.idx], j.idx);
				}
			}
		}
	}
	for(int i=1; i<=n; i++){
		for(int j=1; j<=n; j++){
			if(i != j){
				vector<path_info> pth;
				for(auto &k : gph[i]){
					for(auto &l : gph[j]){
						lint cost = dist[k.idx][l.idx ^ 1];
						pth.push_back({k.pos, l.pos, cost});
					}
				}
				sort(pth.begin(), pth.end());
				if(pth.size() <= 2){
					plist[i][j] = pth;
					continue;
				}
				plist[i][j].push_back(pth[0]);
				plist[i][j].push_back(pth[1]);
				if(pth[0].midl != pth[1].midl && pth[0].midr != pth[1].midr){
					plist[i][j].push_back(pth[2]);
					pi nxt_punkty = pi(-1, -1);
					if(pth[2].midl == pth[1].midl){
						nxt_punkty = pi(pth[2].midl, pth[0].midr);
					}
					else if(pth[2].midl == pth[0].midl){
						nxt_punkty = pi(pth[2].midl, pth[1].midr);
					}
					else if(pth[2].midr == pth[1].midr){
						nxt_punkty = pi(pth[0].midl, pth[2].midr);
					}
					else if(pth[2].midr == pth[0].midr){
						nxt_punkty = pi(pth[1].midl, pth[2].midr);
					}
					for(int k = 3; k < pth.size(); k++){
						if(nxt_punkty.first != pth[k].midl && nxt_punkty.second != pth[k].midr){
							plist[i][j].push_back(pth[k]);
							break;
						}
					}
				}
				else if(pth[0].midl == pth[1].midl){
					for(int x = 0; x < pth.size(); x++){
						if(pth[x].midl != pth[0].midl){
							plist[i][j].push_back(pth[x]);
							pi nxt_punkty = pi(pth[0].midl, pth[x].midr);
							for(int k = x + 1; k < pth.size(); k++){
								if(nxt_punkty.first != pth[k].midl && nxt_punkty.second != pth[k].midr){
									plist[i][j].push_back(pth[k]);
									break;
								}
							}
							break;
						}
					}
				}
				else if(pth[0].midr == pth[1].midr){
					for(int x = 0; x < pth.size(); x++){
						if(pth[x].midr != pth[0].midr){
							plist[i][j].push_back(pth[x]);
							pi nxt_punkty = pi(pth[x].midl, pth[0].midr);
							for(int k = x + 1; k < pth.size(); k++){
								if(nxt_punkty.first != pth[k].midl && nxt_punkty.second != pth[k].midr){
									plist[i][j].push_back(pth[k]);
									break;
								}
							}
							break;
						}
					}
				}
				else assert(0);
			//	for(auto &k : plist[i][j]) printf("(%d -> %d), (%d -> %d), %lld\n", i, k.midl, k.midr, j, k.cost);
			}
		}
	}
}

int a[MAXL];
lint dp[MAXL][4];

int main(){
	scanf("%d %d %d %d",&n,&m,&q,&l);
	preprocess();
	for(int i=0; i<l; i++) scanf("%d",&a[i]);
	for(int i=0; i<q; i++){
		int x, v; scanf("%d %d",&x,&v);
		x--;
		a[x] = v;
		memset(dp, 0x3f, sizeof(dp));
		for(int k=0; k<plist[a[0]][a[1]].size(); k++){
			dp[1][k] = plist[a[0]][a[1]][k].cost;
		}
		for(int k=2; k<l; k++){
			for(int x = 0; x < plist[a[k - 2]][a[k - 1]].size(); x++){
				for(int y = 0; y < plist[a[k - 1]][a[k]].size(); y++){
					if(plist[a[k - 2]][a[k - 1]][x].midr != plist[a[k - 1]][a[k]][y].midl){
						dp[k][y] = min(dp[k][y], dp[k - 1][x] + plist[a[k - 1]][a[k]][y].cost);
					}
				}
			}
		}
		int w = plist[a[l - 2]][a[l - 1]].size();
		lint dap = *min_element(dp[l - 1], dp[l - 1] + w);
		if(dap > 9e17) dap = -1;
		printf("%lld\n", dap);
	}
}

Compilation message (stderr)

wild_boar.cpp: In function 'void preprocess()':
wild_boar.cpp:87:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      for(int k = 3; k < pth.size(); k++){
                     ~~^~~~~~~~~~~~
wild_boar.cpp:95:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      for(int x = 0; x < pth.size(); x++){
                     ~~^~~~~~~~~~~~
wild_boar.cpp:99:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
        for(int k = x + 1; k < pth.size(); k++){
                           ~~^~~~~~~~~~~~
wild_boar.cpp:110:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      for(int x = 0; x < pth.size(); x++){
                     ~~^~~~~~~~~~~~
wild_boar.cpp:114:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
        for(int k = x + 1; k < pth.size(); k++){
                           ~~^~~~~~~~~~~~
wild_boar.cpp: In function 'int main()':
wild_boar.cpp:143:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int k=0; k<plist[a[0]][a[1]].size(); k++){
                ~^~~~~~~~~~~~~~~~~~~~~~~~~
wild_boar.cpp:147:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int x = 0; x < plist[a[k - 2]][a[k - 1]].size(); x++){
                   ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
wild_boar.cpp:148:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int y = 0; y < plist[a[k - 1]][a[k]].size(); y++){
                    ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
wild_boar.cpp: In function 'void preprocess()':
wild_boar.cpp:29:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int s, e, x; scanf("%d %d %d",&s,&e,&x);
                ~~~~~^~~~~~~~~~~~~~~~~~~~~
wild_boar.cpp: In function 'int main()':
wild_boar.cpp:135:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d %d",&n,&m,&q,&l);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
wild_boar.cpp:137:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=0; i<l; i++) scanf("%d",&a[i]);
                         ~~~~~^~~~~~~~~~~~
wild_boar.cpp:139:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int x, v; scanf("%d %d",&x,&v);
             ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 35 / 35
• Subtask 3: 15 / 15
• Subtask 4: 0 / 38