Submission #410115

#	Time	Username	Problem	Language	Result	Execution time	Memory
410115		LptN21	Ronald (COCI17_ronald)	C++14	120 / 120	56 ms	10112 KiB

ronald

#include <bits/stdc++.h>
using namespace std;
#define fastIO ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
#define FF first
#define SS second
#define pb push_back
#define sz(x) (int)x.size()
#define oo 1e9
#define PI acos(-1.0)
#define lb lower_bound
#define ub upper_bound
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;
const int N = 1000+7, M=1e2+1;
const int MOD = 1e9+7;

int n, m, k, t;

int a[N][N], b[N][N];

void flip(int a[N][N], int p) {
    for(int i=1;i<=n;i++)
        a[i][p]=a[p][i]=1-a[i][p];
}
bool solve(int a[N][N]) {
    for(int i=2;i<=n;i++)
        if(!a[i][1]) flip(a, i);
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            if(i!=j&&!a[i][j])
                return 0;
    return 1;
}

signed main() {
    //freopen("test.inp", "r", stdin);
    //freopen("test.out", "w", stdout);
    //fastIO;
    scanf("%d%d", &n, &m);
    int u, v;
    for(int i=1;i<=m;i++) {
        scanf("%d%d", &u, &v);
        a[u][v]=a[v][u]=1;
        b[u][v]=b[v][u]=1;
    }
    if(solve(a)) {
        printf("DA");
        return 0;
    }
    flip(b, 1);
    if(solve(b)) printf("DA");
    else printf("NE");
    return 0;
}
/* stuff you should look for
    - int overflow, array bounds
    - special cases (n=1?)
    - do smth instead of do nothing and stay organized
    - WRITE STUFF DOWN
    - DONT JUST STICK ON ONE APPROACH
*/

Compilation message (stderr)

ronald.cpp: In function 'int main()':
ronald.cpp:40:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
ronald.cpp:43:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |         scanf("%d%d", &u, &v);
      |         ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 15 / 15
• Subtask 3: 15 / 15
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 15 / 15
• Subtask 7: 15 / 15
• Subtask 8: 15 / 15