[POJ3253]Fence Repair

题目链接：http://poj.org/problem?id=3253

单调队列和优先队列（哈夫曼编码）分别实现:

#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <climits>
#include <complex>
#include <fstream>
#include <cassert>
#include <cstdio>
#include <bitset>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <ctime>
#include <set>
#include <map>
#include <cmath>

using namespace std;
typedef long long LL;

const int maxn = 20010;
int n;
int ha, hb, rb, cnt;
LL a[maxn], b[maxn];
LL ans;

int main() {
    // freopen("in", "r", stdin);
    while(~scanf("%d", &n)) {
        memset(b, 0, sizeof(b));
        ha = 0;
        hb = 0;
        rb = 0;
        cnt = 0;
        ans = 0;
        for(int i = 0; i <n ; i++) {
            scanf("%I64d", &a[i]);
        }
        sort(a, a+n);
        while(++cnt < n) {
            int sum = 0;
            if(hb == rb || (ha < n && a[ha] < b[hb])) {
                sum += a[ha];
                ha++;
            }
            else {
                sum += b[hb];
                hb++;
            }
            if(hb==rb || (ha < n && a[ha] < b[hb])) {
                sum += a[ha];
                ha++;
            }
            else {
                sum += b[hb];
                hb++;
            }
            b[rb++] = sum;
            ans += sum;
        }
        printf("%I64d
", ans);
    }
    return 0;
}

#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <climits>
#include <complex>
#include <fstream>
#include <cassert>
#include <cstdio>
#include <bitset>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <ctime>
#include <set>
#include <map>
#include <cmath>

using namespace std;
typedef __int64 LL;

const int maxn = 20010;
int n;
priority_queue<LL, vector<LL>, greater<LL> > pq;
LL ans;

int main() {
    // freopen("in", "r", stdin);
    while(~scanf("%d", &n)) {
        while(!pq.empty())    pq.pop();
        ans = 0;
        LL a;
        for(int i = 0; i < n; i++) {
            scanf("%I64d", &a);
            pq.push(a);
        }
        while(n-- > 1) {
            a = pq.top();
            pq.pop();
            a += pq.top();
            pq.pop();
            pq.push(a);
            ans += a;
        }
        printf("%I64d
",ans);
    }
    return 0;
}