【HDOJ】4355 Party All the Time

好久没做过三分的题目了。

 /* 4355 */
 #include <iostream>
 #include <sstream>
 #include <string>
 #include <map>
 #include <queue>
 #include <set>
 #include <stack>
 #include <vector>
 #include <deque>
 #include <algorithm>
 #include <cstdio>
 #include <cmath>
 #include <ctime>
 #include <cstring>
 #include <climits>
 #include <cctype>
 #include <cassert>
 #include <functional>
 #include <iterator>
 #include <iomanip>
 using namespace std;
 //#pragma comment(linker,"/STACK:102400000,1024000")

 #define sti                set<int>
 #define stpii            set<pair<int, int> >
 #define mpii            map<int,int>
 #define vi                vector<int>
 #define pii                pair<int,int>
 #define vpii            vector<pair<int,int> >
 #define rep(i, a, n)     for (int i=a;i<n;++i)
 #define per(i, a, n)     for (int i=n-1;i>=a;--i)
 #define clr                clear
 #define pb                 push_back
 #define mp                 make_pair
 #define fir                first
 #define sec                second
 #define all(x)             (x).begin(),(x).end()
 #define SZ(x)             ((int)(x).size())
 #define lson            l, mid, rt<<1
 #define rson            mid+1, r, rt<<1|1

 typedef struct {
     double x, w;
 } node_t;

 const double eps = 1e-;
 const int maxn = ;
 node_t nd[maxn];
 int n;

 double calc(double x) {
     double ret = 0.0;

     rep(i, , n)
         ret += pow(fabs(x-nd[i].x), ) * nd[i].w;

     return ret;
 }

 void solve() {
     double l = 1e7;
     double r = -1e7;
     double m1, m2;
     double tmp1, tmp2;

     rep(i, , n) {
         l = min(l, nd[i].x);
         r = max(r, nd[i].x);
     }

     while (fabs(r-l) > eps) {
         m1 = l + (r-l)/;
         m2 = r - (r-l)/;
         tmp1 = calc(m1);
         tmp2 = calc(m2);
         if (tmp1 < tmp2) {
             r = m2;
         } else if (tmp1 > tmp2) {
             l = m1;
         } else {
             l = r;
         }
     }

     double ans = calc(l);
     printf("%.0lf\n", ans);
 }

 int main() {
     ios::sync_with_stdio(false);
     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     int t;

     scanf("%d", &t);
     rep(tt, , t+) {
         scanf("%d", &n);
         rep(i, , n)
             scanf("%lf %lf", &nd[i].x, &nd[i].w);
         printf("Case #%d: ", tt);
         solve();
     }

     #ifndef ONLINE_JUDGE
         printf("time = %d.\n", (int)clock());
     #endif

     return ;
 }