Renting Boats

Renting Boats

http://acm.fzu.edu.cn/problem.php?pid=1436

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Time Limit:1sMemory limit:32MAccepted Submit:187Total Submit:412

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Problem Description

Yangtse Rive Barge Club has set up n barge hiring stops numbered 1, 2, … , n along the Changjiang

River. Passengers can hire barges from any of these stops, and return the barges to one of the stops afterward. The rent for an barge from stop i to stop j is r(i,j) (1<=i,j<=n). Your task is to design an

algorithm to minimize the rent of hiring barges when you traveling from stop 1 to stop n.

Input

There are multiple test cases. The first line of each case contains an integer n indicating the number of the stops (n<=200). The following n-1 lines are the rent between any two stops. The ith following line contains n-i integers indicating r(i,j) (i < j <= n).

Output

For each case, output one line representing the minimal rent.

Sample Input

35 157

Sample Output

12

有关图的题目，用Dijkstra算法

#include<cstdio>#include<cstring>#define Min 99999int MGraph[210][210];void Dijkstra(int lowcost[],int NumOfBoats){int i,j,min,local;bool visited[210];memset(visited,false,sizeof(visited));for(i=1;i<=NumOfBoats;i++)lowcost[i]=MGraph[1][i];for(i=2;i<=NumOfBoats;i++){min=Min;for(j=2;j<=NumOfBoats;j++){if(lowcost[j]<min&&visited[j]!=true){min=lowcost[j];local=j;}}visited[local]=true;for(j=2;j<=NumOfBoats;j++){if(!visited[j]){if(lowcost[j]>MGraph[local][j]+lowcost[local])lowcost[j]=MGraph[local][j]+lowcost[local];}}}}int main(){int i,j,NumOfBoats,lowcost[210];while(scanf("%d",&NumOfBoats)!=EOF){memset(MGraph,0,sizeof(MGraph));memset(lowcost,0,sizeof(lowcost));for(i=1;i<=NumOfBoats;i++){for(j=1;j<=NumOfBoats;j++)if(i!=j) MGraph[i][j]=Min;}for(i=1;i<NumOfBoats;i++){for(j=i+1;j<=NumOfBoats;j++)scanf("%d",&MGraph[i][j]);}Dijkstra(lowcost,NumOfBoats);printf("%d/n",lowcost[NumOfBoats]);}return 0;}