Submission #186614

#	Time	Username	Problem	Language	Result	Execution time	Memory
186614		Ruxandra985	Alternating Current (BOI18_alternating)	C++14	55 / 100	3020 ms	1108 KiB

alternating

#include <bits/stdc++.h>
#define DIMN 100010
using namespace std;
pair <int,int> v[DIMN];
int d[DIMN] , cer[DIMN] , f[DIMN] , sol[DIMN];
int main()
{
    FILE *fin = stdin;
    FILE *fout = stdout;
    int n , m , i , j , ok , poz , what;
    fscanf (fin,"%d%d",&n,&m);
    for (i=1;i<=m;i++){
        fscanf (fin,"%d%d",&v[i].first,&v[i].second);
        if (v[i].first <= v[i].second){
            for (j = v[i].first ; j <= v[i].second ; j++){
                d[j]++;
            }
        }
        else {
            for (j = v[i].first ; j <= n ; j++){
                d[j]++;
            }
            for (j = 1 ; j <= v[i].second ; j++){
                d[j]++;
            }
        }
    }
    for (j=1;j<=m;j++){
 
        ok = 0;
        for (i=1;i<=n;i++){
            if (d[i] == 1 && cer[i] < 3 && cer[i] > 0)
                ok = i;
        }
 
        if (ok){
 
            for (i=1;i<=m;i++){
                if (!f[i]){ /// inca e relevant
                    if (v[i].first <= v[i].second && v[i].first <= ok && ok <= v[i].second){
                        poz = i;
                        f[i] = 1;
                    }
                    else if (v[i].first > v[i].second && (ok >= v[i].first || ok <= v[i].second)){
                        poz = i;
                        f[i] = 1;
                    }
                }
            }
 
            what = cer[ok];
 
        }
        else {
            what = 1;
            for (i=1;i<=m;i++){
                if (!f[i]){
                    poz = i;
                    f[i] = 1;
                    break;
                }
            }
        }
        sol[poz] = what - 1;
        /// update
 
        for (i=1;i<=n;i++){
            if ((v[poz].first <= v[poz].second && v[poz].first <= i && i <= v[poz].second) ||
                (v[poz].first > v[poz].second && (i >= v[poz].first || i <= v[poz].second))){
                /// i e afectat de interval
                d[i]--;
                if (cer[i] == 0){
                    if (what == 1)
                        cer[i] = 2;
                    else cer[i] = 1;
                }
                else if (cer[i] == 3){}
                else { /// e 1 sau 2 , cere ceva si i se da
                    if (cer[i] == what){
                        cer[i] = 3;
                    }
                }
 
            }
        }
 
    }
    for (i=1;i<=n;i++){
        if (cer[i] != 3){
            fprintf (fout,"impossible");
            return 0;
        }
    }
    for (i=1;i<=m;i++){
        fprintf (fout,"%d",sol[i]);
    }
    return 0;
}

Compilation message (stderr)

alternating.cpp: In function 'int main()':
alternating.cpp:11:12: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     fscanf (fin,"%d%d",&n,&m);
     ~~~~~~~^~~~~~~~~~~~~~~~~~
alternating.cpp:13:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         fscanf (fin,"%d%d",&v[i].first,&v[i].second);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
alternating.cpp:64:18: warning: 'poz' may be used uninitialized in this function [-Wmaybe-uninitialized]
         sol[poz] = what - 1;
         ~~~~~~~~~^~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 20 / 20
• Subtask 3: 22 / 22
• Subtask 4: 0 / 19
• Subtask 5: 0 / 26