Submission #20980

#	Time	Username	Problem	Language	Result	Execution time	Memory
20980		ainta	Ili (COI17_ili)	C++14	100 / 100	2996 ms	2680 KiB

ili

#include<cstdio>
#include<algorithm>
#include<vector>
using namespace std;
int n, m, E[20100][2];
char p[10100];
vector<int> G[20100];
int Get(char *a){
    int i, s = 0;
    for(i=1;a[i];i++)s=s*10+a[i]-'0';
    if(a[0]=='x')return s;
    return s+n;
}
int v[20100];
struct point{
    int a, b, c;
}w[20100];
void DFS(int a){
    v[a]=1;
    if(a<=n)return;
    int i;
    for(i=0;i<2;i++){
        if(!v[E[a][i]])DFS(E[a][i]);
    }
}
int Q[20100], head, tail;
int vv[20100];
bool Pos(int a, int b){
    int i;
    if(!a){
        for(i=1;i<=n+m;i++)v[i]=0;
        for(i=1;i<=m;i++){
            if(p[i]=='1' && !v[n+i]) v[n+i] = 2;
        }
        for(i=1;i<=m;i++){
            if(p[i]=='0' && !v[n+i])DFS(n+i);
        }
    }
    else{
        for(i=1;i<=n+m;i++)v[i]=vv[i];
        if(b==1) DFS(a);
        else v[a] = b;
    }
    for(i=1;i<=m;i++){
        if(!v[w[i].c]){
            if(v[w[i].a] == 1 && v[w[i].b] == 1) v[w[i].c] = 1;
        }
    }
    head = tail = 0;
    for(i=1;i<=n+m;i++){
        if(v[i]==2)Q[++tail] = i;
    }
    while(head < tail){
        int x = Q[++head];
        if(x > n){
            if(v[E[x][0]] == 1 && v[E[x][1]] == 0){
                v[E[x][1]] = 2;
                Q[++tail] = E[x][1];
            }
            if(v[E[x][1]] == 1 && v[E[x][0]] == 0){
                v[E[x][0]] = 2;
                Q[++tail] = E[x][0];
            }
        }
        for(i=0;i<G[x].size();i++){
            if(!v[G[x][i]]){
                v[G[x][i]] = 2;
                Q[++tail] = G[x][i];
            }
        }
    }
    for(i=1;i<=m;i++){
        if(v[w[i].a]==1 && v[w[i].b]==1 && v[w[i].c] == 2)return false;
        if((v[w[i].a]==2 || v[w[i].b]==2) && v[w[i].c] == 1)return false;
    }
    return true;
}
int main(){
    int i;
    scanf("%d%d",&n,&m);
    scanf("%s",p+1);
    char p1[20], p2[20];
    for(i=1;i<=m;i++){
        scanf("%s%s",p1,p2);
        int t1 = Get(p1), t2 = Get(p2);
        E[n+i][0] = t1;
        E[n+i][1] = t2;
        G[t1].push_back(n+i);
        G[t2].push_back(n+i);
        w[i].a = t1, w[i].b = t2, w[i].c = n+i;
    }
    DFS(0);
    Pos(0,0);
    for(i=1;i<=n+m;i++)vv[i] = v[i];
    for(i=1;i<=m;i++){
        if(vv[n+i]){
            printf("%d",vv[n+i]-1);
            continue;
        }
        if(!Pos(n+i, 1)){
            printf("1");
        }
        else if(!Pos(n+i, 2)){
            printf("0");
        }
        else printf("?");
    }
}

Compilation message (stderr)

ili.cpp: In function 'bool Pos(int, int)':
ili.cpp:65:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(i=0;i<G[x].size();i++){
                  ^
ili.cpp: In function 'int main()':
ili.cpp:80:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
                        ^
ili.cpp:81:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s",p+1);
                    ^
ili.cpp:84:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%s%s",p1,p2);
                            ^

• Subtask 1: 7 / 7
• Subtask 2: 42 / 42
• Subtask 3: 51 / 51