poj_1062

这道题目不难，只要建好图就行。我们在图中新建一个新的点0，从0出发的到其他点的值就是该物品的原价值，那么我们新建立一个二维数组price[i][j],表示i物品兑换j物品的价值，则price[0][i]就是i物品的原价值。然后我们遍历每一个物品，对于每一个物品，我们都假设它是当前等级最高的那个，然后我们把比它价值高或者和它价值差超过m的那些物品设置为不可访问，接着用最短路跑一遍。经过n次循环后，输出的就是最小的价值。

#include<stdio.h>#include<iostream>#include<string>#include<string.h>#include<algorithm>#include<iomanip>#include<vector>#include<time.h>#include<queue>#include<stack>#include<iterator>#include<math.h>#include<stdlib.h>#include<limits.h>#include<map>//#define ONLINE_JUDGE#define eps 1e-10#define INF 0x7fffffff#define FOR(i,a) for((i)=0;i<(a);(i)++)#define MEM(a) (memset((a),0,sizeof(a)))#define sfs(a) scanf("%s",a)#define sf(a) scanf("%d",&a)#define sfI(a) scanf("%I64d",&a)#define pf(a) printf("%d\n",a)#define pfI(a) printf("%I64d\n",a)#define pfs(a) printf("%s\n",a)#define sfd(a,b) scanf("%d%d",&a,&b)#define sft(a,b,c)scanf("%d%d%d",&a,&b,&c)#define for1(i,a,b) for(int i=(a);i<b;i++)#define for2(i,a,b) for(int i=(a);i<=b;i++)#define for3(i,a,b)for(int i=(b);i>=a;i--)#define MEM1(a) memset(a,0,sizeof(a))#define MEM2(a) memset(a,-1,sizeof(a))#define ll __int64const double PI=acos(-1.0);template<class T> T gcd(T a,T b){return b?gcd(b,a%b):a;}template<class T> T lcm(T a,T b){return a/gcd(a,b)*b;}template<class T> inline T Min(T a,T b){return a<b?a:b;}template<class T> inline T Max(T a,T b){return a>b?a:b;}using namespace std;int n,m,k;int s;#define N 110int lev[N],num[N];int price[N][N];int vis[N];int dijkstra(){    int dis[N];//  memset(dis,0x3f3f3f3f,sizeof dis);    for(int i=1;i<=n;i++)        dis[i] = price[0][i];    for(int i=1;i<n;i++){        int mmin = INF;        int flag = -1;        for(int j=1;j<=n;j++)            if(!vis[j]&&mmin>dis[j])                mmin = dis[flag=j];        if(flag == -1) break;        vis[flag] = 1;        for(int j=1;j<=n;j++)            if(!vis[j] && price[flag][j]>0 && dis[j]>price[flag][j]+mmin)                dis[j] = price[flag][j]+mmin;    }    return dis[1];}int main(){#ifndef ONLINE_JUDGE    freopen("in.txt","r",stdin);//  freopen("out.txt","w",stdout);#endif    while(scanf("%d%d",&m,&n)!=EOF){        memset(price,0,sizeof price);        int u,w;        for(int i=1;i<=n;i++){            scanf("%d%d%d",&price[0][i],&lev[i],&num[i]);            for(int j=0;j<num[i];j++){                scanf("%d%d",&u,&w);                price[u][i] = w;            }        }        int ans = INF;        for(int i=1;i<=n;i++){            memset(vis,0,sizeof vis);            int mmax = lev[i];          //假设这是当前最高的等级            for(int j=1;j<=n;j++){                if(lev[j]>mmax || mmax-lev[j]>m)    //不符合的点就不访问了                    vis[j] = 1;            }            ans = Min(ans,dijkstra());        }        printf("%d\n",ans);    }return 0;}