Submission #31546

#	Time	Username	Problem	Language	Result	Execution time	Memory
31546		ngkan146	Senior Postmen (BOI14_postmen)	C++98	55 / 100	308 ms	16632 KiB

postmen

#include <bits/stdc++.h>
using namespace std;
int ctrl[500005];
int nxt[500005], prv[500005], id[1000005];
int head[500005], en[500005];
bool visited[1000005];
int n,m;
int euler[1000005], eulersize;
int q[1000005], qsize;
void dfs(){
    q[qsize++] = 1;
    while(qsize){
        int u = q[qsize-1];
        bool mjk = 0;
        for(;ctrl[u];ctrl[u] = nxt[ctrl[u]]){
            int v = (u ^ head[id[ctrl[u]]] ^ en[id[ctrl[u]]]);
            if (visited[id[ctrl[u]]]) continue;
            mjk = 1;
            visited[id[ctrl[u]]] = 1;
            q[qsize++] = v;
            break;
        }

        if(mjk) continue;

        euler[eulersize++] = u;
        --qsize;
    }
}
int st[1000005], stsize;
bool used[1000005];
int main(){
    scanf("%d %d",&n,&m);
    int cnt = 0;
    for(int i=1;i<=m;++i){
        int x,y;
        scanf("%d %d",&x,&y);

        if (!ctrl[x]){
            ctrl[x] = ++cnt;
            id[cnt] = i;
            prv[x] = cnt;
        }
        else
            nxt[prv[x]] = ++cnt,
            id[cnt] = i,
            prv[x] = cnt;

        if (!ctrl[y]){
            ctrl[y] = ++cnt;
            id[cnt] = i;
            prv[y] = cnt;
        }
        else
            nxt[prv[y]] = ++cnt,
            id[cnt] = i,
            prv[y] = cnt;


        head[i] = x;
        en[i] = y;
    }

    dfs();

    for(int i=0;i<eulersize;++i){
        if (used[euler[i]]){
            while(st[stsize-1] != euler[i]){
                printf("%d ",st[stsize-1]);
                used[st[stsize-1]] = 0;
                --stsize;
            };
            printf("%d\n",euler[i]);
        }
        else{
            st[stsize++] = euler[i];
            used[euler[i]] = 1;
        }
    }
}

Compilation message (stderr)

postmen.cpp: In function 'int main()':
postmen.cpp:33:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~~
postmen.cpp:37:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d",&x,&y);
         ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 0 / 45