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POJ No 3614 Sunscreen 优先队列 贪心
Time Limit: 1000MS | Memory Limit: 65536K | |
Total Submissions: 6410 | Accepted: 2239 |
Description
To avoid unsightly burns while tanning, each of the C (1 ≤ C ≤ 2500) cows must cover her hide with sunscreen when they‘re at the beach. Cow i has a minimum and maximum SPF rating (1 ≤ minSPFi ≤ 1,000; minSPFi ≤ maxSPFi ≤ 1,000) that will work. If the SPF rating is too low, the cow suffers sunburn; if the SPF rating is too high, the cow doesn‘t tan at all........
The cows have a picnic basket with L (1 ≤ L ≤ 2500) bottles of sunscreen lotion, each bottle i with an SPF rating SPFi (1 ≤ SPFi ≤ 1,000). Lotion bottle i can cover coveri cows with lotion. A cow may lotion from only one bottle.
What is the maximum number of cows that can protect themselves while tanning given the available lotions?
Input
* Line 1: Two space-separated integers: C and L
* Lines 2..C+1: Line i describes cow i‘s lotion requires with two integers: minSPFi and maxSPFi
* Lines C+2..C+L+1: Line i+C+1 describes a sunscreen lotion bottle i with space-separated integers: SPFi and coveri
Output
A single line with an integer that is the maximum number of cows that can be protected while tanning
Sample Input
3 23 102 51 56 24 1
Sample Output
2
#include <iostream>#include <algorithm>#include <cstring>#include <cstdio>#include <queue>#include <functional>#include <utility>using namespace std;/*3 2 // C只牛 L个防晒霜 C 行 3 10 minSPF, maxSPF 2 51 5L行 6 2 每种数量, 固定的阳光强度 4 1*/ const int maxn = 100000;int C, L; // C只奶牛 , Ltypedef pair<int, int> P; // minSPF, maxSPF //小值先出 priority_queue<int, vector<int>, greater<int> > q;P cow[maxn], bot[maxn]; //牛(min,max) 和 防晒霜(固定的阳光数, 数量) void solve();void input();void input(){ scanf("%d%d", &C, &L); for (int i = 0; i < C; i++) { scanf("%d%d", &cow[i].first, &cow[i].second); } for (int i = 0; i < L; i++) { scanf("%d%d", &bot[i].first, &bot[i].second); }}void solve(){ input(); sort(cow, cow + C); //按照最小值阳光强度升序 sort(bot, bot + L); //(first)按照能固定的阳光强度升序 int j = 0, ans = 0; //当 L 个 防晒霜 for (int i = 0; i < L; i++) { //将最小值阳光 和 固定的阳光强度 比较 while (j < C && cow[j].first <= bot[i].first) { q.push(cow[j].second); //添加到优先队列 (最小值阳光) j++; } //如果 最小值阳光 序列不空,当前 防晒霜未用完 while (!q.empty() && bot[i].second) { int x = q.top(); q.pop(); // 最小值 小于 能固定的阳光, 方案不存在 if (x < bot[i].first) continue; //否则, ans++; //当前防晒霜-- bot[i].second--; } } printf("%d\n", ans);}int main(){ solve(); return 0;}
POJ No 3614 Sunscreen 优先队列 贪心