pku1018 Communication System

http://poj.org/problem?id=1018

DP，写的好蒙。。。

#include <stdio.h>
#include <map>

using namespace std;

#define N 110

int b[N][N], p[N][N];
int dp[N][N*N];
const int maxint = 1<<30;

int main()
{
    int i, j, t, n, m, x, y, k;
    float max1, temp1;
    map<int, int> map1, map2;
    map<int, int>::iterator it;
    scanf("%d", &t);
    while(t-- && scanf("%d", &n))
    {
        map1.clear();
        map2.clear();
        k = 1;
        for(i=1; i<=n; i++)
        {
            scanf("%d", &m);
            b[i][0] = m;
            for(j=1; j<=m; j++)
            {
                scanf("%d%d", &x, &y);
                if(map1.find(x) == map1.end())
                {
                    map1.insert(make_pair(x, k));
                    k ++;
                }
                b[i][j] = x;
                p[i][j] = y;
            }
        }
        for(i=0; i<N*N; i++)
        {
            dp[0][i] = dp[1][i] = maxint;
        }
        for(j=1; j<=b[1][0]; j++)
        {
            dp[0] [map1[b[1][j]]] = min(dp[0] [map1[b[1][j]]], p[1][j]);
        }
        for(i=2; i<=n; i++)
        {
            for(j=1; j<=b[i][0]; j++)
            {
                for(it=map1.begin(); it!=map1.end(); it++)
                {
                    if(dp[0][(*it).second]==maxint)
                    {
                        continue;
                    }
                    if((*it).first <= b[i][j])
                    {
                        dp[1][map1[(*it).first]] = min(dp[1][map1[(*it).first]], dp[0][map1[(*it).first]]+p[i][j]);
                    }
                    else
                    {
                        dp[1][map1[b[i][j]]] = min(dp[1][map1[b[i][j]]], dp[0][map1[(*it).first]]+p[i][j]);
                    }
                }
            }
            for(j=0; j<N*N; j++)
            {
                dp[0][j] = dp[1][j];
                dp[1][j] = maxint;
            }
        }
        for(it=map1.begin(); it!=map1.end(); it++)
        {
            map2.insert(make_pair((*it).second, (*it).first));
        }
        max1 = -1;
        for(j=0; j<N*N; j++)
        {
            if(dp[0][j]==maxint)
            {
                continue;
            }
            temp1 = (float)map2[j] / (float)dp[0][j];
            if(temp1 > max1)
            {
                max1 = temp1;
            }
        }
        printf("%.3f\n", max1);
    }
    return 0;
}