제출 #1034642

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1034642		anango	Paths (BOI18_paths)	C++17	0 / 100	1 ms	604 KiB

paths

#include <bits/stdc++.h>
#define int long long
using namespace std;
int INF = 1LL<<30;

signed main() {
    #ifndef ONLINE_JUDGE
        // for getting input from input.txt
        freopen("input.txt", "r", stdin);
        // for writing output to output.txt
        freopen("output.txt", "w", stdout);
    #endif
    #ifdef ONLINE_JUDGE
    	ios_base::sync_with_stdio(false);
    	cin.tie(NULL);
    #endif //fast IO
    int n,m,k; cin >> n >> m >> k;
    vector<vector<int>> adjlist(n);
    vector<int> col(n); for (int i=0; i<n; i++) {cin >> col[i]; col[i]--;}
    for (int i=0; i<m; i++) {
        int u,v; cin >> u >> v; u--; v--;
        adjlist[u].push_back(v); adjlist[v].push_back(u);
    }
    int dp[n][1<<k];
    for (int i=0; i<n; i++) {
        for (int j=0; j<1<<k; j++) {
            dp[i][j] = 0;
        }
    }
    //dp[i][j] = number of paths with  this bitmask of colours used, ending in this vertex
    for (int i=0; i<n; i++) {
        dp[i][1<<col[i]]++;
    }
    for (int mask=1; mask<1<<k; mask++) {
        for (int i=0; i<n; i++) {
            if (mask&(1<<col[i])==0) continue;
            for (int j:adjlist[i]) {
                dp[i][mask]+=dp[j][mask^(1<<col[i])];
            }
        }
    }
    int su=0;
    for (int i=0; i<n; i++) {
        for (int j=0; j<1<<k; j++) {
            su+=dp[i][j];
        }
    }
    cout << su-n << endl;
    
}

컴파일 시 표준 에러 (stderr) 메시지

paths.cpp: In function 'int main()':
paths.cpp:36:33: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   36 |             if (mask&(1<<col[i])==0) continue;
      |                      ~~~~~~~~~~~^~~
paths.cpp:9:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |         freopen("input.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
paths.cpp:11:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |         freopen("output.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 23
• Subtask 2: 0 / 20
• Subtask 3: 0 / 27
• Subtask 4: 0 / 30