uva 590 Always on the run

简单的动态规划

#include <stdio.h>
#include <vector>
using namespace std;

struct arr_node{
vector<int> price;
};
struct arr_node arr[15][15];
int dp[1001][15];

void func(int citys, int days){
int i, j, k, price, flight_n;
static int case_n = 1;

dp[0][1] = 0;
for(j=2; j<=citys; j++)
dp[0][j] = -1;

for(i=1; i<=days; i++){
for(j=1; j<=citys; j++){
dp[i][j] = -1;
for(k=1; k<=citys; k++){ //从第k个城市到第j个城市
if(k == j)
continue;

flight_n = arr[k][j].price.size();
price = arr[k][j].price[i%flight_n ? i%flight_n-1 : flight_n-1];
if( price && dp[i-1][k]!=-1 && (price+dp[i-1][k]<dp[i][j] || dp[i][j]==-1) )
dp[i][j] = price+dp[i-1][k];
}
}
}

printf("Scenario #%d\n", case_n++);
if(dp[days][citys] == -1){
printf("No flight possible.\n\n");
}
else{
printf("The best flight costs %d.\n\n", dp[days][citys]);
}
}

int main(void){
int citys, days;
int i, j, k;
int price;

//freopen("input.dat", "r", stdin);
while(scanf("%d %d", &citys, &days) != EOF){
if(0==citys && 0==days)
break;

for(i=1; i<=citys; i++){
for(j=1; j<=citys; j++){
if(i == j) continue;
scanf("%d", &k);
arr[i][j].price.clear();
while(k--){
scanf("%d", &price);
arr[i][j].price.push_back(price);
}
}
}
func(citys, days);
}
return 0;
}