207

Author: lazzzis

207/main.cpp

@@ -0,0 +1,71 @@
+#include <iostream>
+#include <string>
+#include <cstring>
+#include <vector>
+#include <cstdlib>
+#include <cmath>
+#include <queue>
+#include <iomanip>
+#include <algorithm>
+#ifdef WINDOWS
+#include <direct.h>
+#define GetCurrentDir _getcwd
+#else
+#include <unistd.h>
+#define GetCurrentDir getcwd
+#endif
+
+using namespace std;
+
+#ifndef ONLINE_JUDGE
+std::string GetCurrentWorkingDir( void ) {
+  char buff[10000];
+  GetCurrentDir( buff, 10000 );
+  std::string current_working_dir(buff);
+  return current_working_dir;
+}
+#endif
+
+#define REP(i,n) for(int i = 0; i < (n); i++)
+#define REPS(i,s,n) for(int i = (s); i < (n); i++)
+
+const int MAXN = 1000 + 50;
+int vis[MAXN];
+int c[MAXN][MAXN];
+
+bool dfs(int course, int numCourses) {
+    vis[course] = -1;
+    for (int i = 0; i < numCourses; i++) {
+        if (!c[course][i]) continue;
+        if (vis[i] < 0) return false;
+        if (!vis[i] && !dfs(i, numCourses)) return false;
+    }
+    vis[course] = 1;
+    return true;
+}
+
+bool canFinish(int numCourses, vector<pair<int, int>>& prerequisites) {
+    memset(vis, 0, sizeof(vis));
+    memset(c, 0, sizeof(c));
+    for (auto dependencies : prerequisites) {
+        c[dependencies.first][dependencies.second] = 1;
+    }
+    REP(i, numCourses) {
+        if (!vis[i] && !dfs(i, numCourses)) return false;
+    }
+    return true;
+}
+
+int main(int argc, char const *argv[]) {
+    #ifndef ONLINE_JUDGE
+    // string cwd = GetCurrentWorkingDir() + "/test.in";
+    // freopen(cwd.c_str(), "r", stdin);
+    #endif
+    vector<pair<int, int>> s{
+        make_pair(1, 0),
+        make_pair(0, 1),
+        make_pair(2, 3),
+        make_pair(3, 4)
+    };
+    cout << canFinish(3, s) << endl;
+}

README.md

@@ -90,6 +90,7 @@
 - [169 Majority Element](./169)
 - [189 Rotate Array](./189)
 - [206 Reverse Linked List](./206)
+- [207 Course Schedule](./207)
 - [209 Minimum Size Subarray Sum](./209)
 - [217 Contains Duplicate](./217)
 - [219 Contains Duplicate II](./219)