UVA 662 Fast Food + classic Dynamic Planning

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Previously also encountered this type of DP, the feeling is that the state is not good definition and transfer, the original definition of the state is always considered dp[i][j] should be transferred from the dp[i-1][j-1], which will lead to the need to remember the front i-1 step of all states, and then the transfer equation can not be written. For this problem, we define state Dp[i][j] to represent the minimum cost of building I warehouses for the first J restaurants, and then state to dp[i][j]=dp[i-1][k-1]+cost[k][j], meaning: The former i-1 warehouses that have been established are responsible for the former k-1 restaurants, Then the I restaurant is responsible for the first k–j restaurants, of which k<=i<=j; And then it's the subject that needs to be printed every time, and we'll just push back in the final state.

The code is as follows:

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>using namespace STD;intdp[ -][ -],n,k;inta[222],cost[ -][ -];int ABS(intx) {if(x<0) X=-x;returnx;}intCalintIintj) {intM= (I+J)/2;intsum=0; for(intd=i;d<=j;d++) sum+=ABS(A[d]-a[m]);returnsum;}voidPrintintIintj) {if(i==1)    {intD= (I+J)/2;printf("Depot%d at restaurant%d serves restaurants%d to%d\n", i,d,i,j);return; }Else{ for(intd=i;d<=j;d++) {if(dp[i-1][d-1]+cost[d][j]==dp[i][j]) {print (I-1, d1);printf("Depot%d at restaurant%d serves restaurants%d to%d\n", I, (d+j)/2, d,j);return; }        }    }}intMain () {///freopen ("In.txt", "R", stdin);    intCase=0; while(scanf("%d%d", &n,&k)!=eof) {if(n==0&&k==0) Break; for(intI=1; i<=n;i++)scanf("%d", &a[i]);memset(DP,0x3f,sizeof(DP)); for(intI=1; i<=n;i++) for(intj=i;j<=n;j++) cost[i][j]=cal (I,J); for(intI=1; i<=n;i++) dp[1][i]=cost[1][i]; for(intI=2; i<=k;i++) for(intj=i;j<=n;j++) { for(intd=i;d<=j;d++) Dp[i][j]=min (dp[i-1][d-1]+COST[D][J],DP[I][J]); }printf("Chain%d\n", ++case); Print (k,n);printf("total distance sum =%d\n\n", Dp[k][n]); }return 0;}

UVA 662 Fast Food + classic Dynamic Planning