11-yuyu0830

11-yuyu0830

yuyu0830/그리디/1826.cpp

@@ -0,0 +1,72 @@
+#include <iostream>
+#include <queue>
+
+using namespace std;
+
+typedef pair<int, int> ii;
+
+struct cmp{
+    bool operator() (ii &a, ii &b) {
+        if (a.first > b.first) return true;
+        return false;
+    }
+};
+
+struct cmpB{
+    bool operator() (ii &a, ii &b) {
+        if (a.second < b.second) return true;
+        return false;
+    }
+};
+
+int main() {
+    priority_queue<ii, vector<ii>, cmp> q;
+
+    int n; cin >> n;
+    for (int i = 0; i < n; i++) {
+        int a, b; cin >> a >> b;
+        q.push(make_pair(a, b));
+    }
+
+    int dest, fuel; cin >> dest >> fuel;
+    int cur = 0, ans = 0;
+
+    priority_queue<ii, vector<ii>, cmpB> reachable;
+
+    while (cur <= dest) {
+        while (!q.empty()) {
+            if (q.top().first <= cur + fuel) {
+                reachable.push(q.top());
+                q.pop();
+            }
+            else break;
+        }
+
+        while (true) {
+            if (cur + fuel >= dest) {
+                printf("%d\n", ans);
+                return 0;
+            }
+
+            if (reachable.empty()) {
+                printf("-1\n");
+                return 0;
+            }
+
+            int f = reachable.top().first;
+            int s = reachable.top().second;
+
+            if (f > cur) fuel -= f - cur;
+            fuel += s;
+
+            cur = f > cur ? f : cur;
+            ans++;
+
+            reachable.pop();
+
+            if (q.top().first <= cur + fuel) break;
+        }
+    }
+
+    printf("%d\n", ans);
+}