제출 #233725

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
233725		duality	Olympic Bus (JOI20_ho_t4)	C++11	100 / 100	394 ms	4472 KiB

ho_t4

#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
typedef long long int LLI;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef vector<pii> vpii;

struct edge { int v,c,d,i; };
vector<edge> adjList[2][200];
int dist1[200],dist2[200],dist3[200],dist4[200],dist5[200],dist6[200];
priority_queue<pii> H;
int inTree[50000];
int findPath(int u,int *dist,int N,int r,edge rev) {
    int i;
    for (i = 0; i < N; i++) dist[i] = -1;
    dist[u] = 0,H.push(mp(0,u));
    while (!H.empty()) {
        int u = H.top().second;
        int d = -H.top().first;
        H.pop();

        if (d > dist[u]) continue;
        for (i = 0; i < adjList[r][u].size(); i++) {
            int v = adjList[r][u][i].v;
            if (adjList[r][u][i].i == rev.i) continue;
            if ((dist[v] == -1) || (dist[u]+adjList[r][u][i].c < dist[v])) {
                dist[v] = dist[u]+adjList[r][u][i].c;
                if (rev.i == -1) inTree[adjList[r][u][i].i] = 1;
                H.push(mp(-dist[v],v));
            }
        }
        if (u == rev.v) {
            int v = rev.d;
            if ((dist[v] == -1) || (dist[u]+rev.c < dist[v])) {
                dist[v] = dist[u]+rev.c;
                H.push(mp(-dist[v],v));
            }
        }
    }
    return 0;
}
int main() {
    int i;
    int N,M;
    int U,V,C,D;
    scanf("%d %d",&N,&M);
    for (i = 0; i < M; i++) {
        scanf("%d %d %d %d",&U,&V,&C,&D);
        U--,V--;
        adjList[0][U].pb((edge){V,C,D,i});
        adjList[1][V].pb((edge){U,C,D,i});
    }

    int j,ans = 2e9;
    findPath(0,dist1,N,0,(edge){-1,-1,-1,-1}),findPath(N-1,dist2,N,1,(edge){-1,-1,-1,-1});
    findPath(0,dist3,N,1,(edge){-1,-1,-1,-1}),findPath(N-1,dist4,N,0,(edge){-1,-1,-1,-1});
    if ((dist1[N-1] != -1) && (dist4[0] != -1)) ans = dist1[N-1]+dist4[0];
    for (i = 0; i < N; i++) {
        for (j = 0; j < adjList[0][i].size(); j++) {
            int v = adjList[0][i][j].v;
            if (!inTree[adjList[0][i][j].i]) {
                if ((dist1[v] != -1) && (dist2[i] != -1) && (dist4[0] != -1))
                    ans = min(ans,dist1[v]+dist2[i]+dist4[0]+adjList[0][i][j].c+adjList[0][i][j].d);
                if ((dist1[N-1] != -1) && (dist4[v] != -1) && (dist3[i] != -1))
                    ans = min(ans,dist1[N-1]+dist4[v]+dist3[i]+adjList[0][i][j].c+adjList[0][i][j].d);
                if ((dist1[v] != -1) && (dist2[i] != -1) && (dist4[v] != -1) && (dist3[i] != -1))
                    ans = min(ans,dist1[v]+dist2[i]+dist4[v]+dist3[i]+2*adjList[0][i][j].c+adjList[0][i][j].d);
            }
        }
    }
    for (i = 0; i < N; i++) {
        for (j = 0; j < adjList[0][i].size(); j++) {
            int v = adjList[0][i][j].v;
            if (inTree[adjList[0][i][j].i]) {
                int x = 2e9;
                if ((dist1[v] != -1) && (dist2[i] != -1) && (dist4[0] != -1))
                    x = min(x,dist1[v]+dist2[i]+dist4[0]+adjList[0][i][j].c+adjList[0][i][j].d);
                if ((dist1[N-1] != -1) && (dist4[v] != -1) && (dist3[i] != -1))
                    x = min(x,dist1[N-1]+dist4[v]+dist3[i]+adjList[0][i][j].c+adjList[0][i][j].d);
                if ((dist1[v] != -1) && (dist2[i] != -1) && (dist4[v] != -1) && (dist3[i] != -1))
                    x = min(x,dist1[v]+dist2[i]+dist4[v]+dist3[i]+2*adjList[0][i][j].c+adjList[0][i][j].d);
                if (x >= ans) continue;
                edge e = adjList[0][i][j];
                e.d = i;
                findPath(0,dist5,N,0,e),findPath(N-1,dist6,N,0,e);
                if ((dist5[N-1] != -1) && (dist6[0] != -1)) ans = min(ans,dist5[N-1]+dist6[0]+adjList[0][i][j].d);
            }
        }
    }
    if (ans == 2e9) printf("-1\n");
    else printf("%d\n",ans);

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

ho_t4.cpp: In function 'int findPath(int, int*, int, int, edge)':
ho_t4.cpp:25:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i = 0; i < adjList[r][u].size(); i++) {
                     ~~^~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp: In function 'int main()':
ho_t4.cpp:61:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (j = 0; j < adjList[0][i].size(); j++) {
                     ~~^~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp:74:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (j = 0; j < adjList[0][i].size(); j++) {
                     ~~^~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp:48:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d",&N,&M);
     ~~~~~^~~~~~~~~~~~~~~
ho_t4.cpp:50:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d %d %d",&U,&V,&C,&D);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 11 / 11
• Subtask 3: 21 / 21
• Subtask 4: 63 / 63