hdu 1160 FatMouse's Speed（最长不下降子序列+输出路径）

题意：

FatMouse believes that the fatter a mouse is, the faster it runs. To disprove this, you want to take the data on a collection of mice and put as large a subset of this data as possible into a sequence so that the weights are increasing, but the speeds are decreasing.

要求输出哪些FatMouse被选中了，按顺序输出。

 

思路：

最长不下降子序列，且要记录路径。

看代码

 

代码：

struct node{
    int weight, speed, index;
}
mice[10005];

int dp[10005];
int path[10005];
int finalPath[10005];


bool cmp(node a,node b){
    if(a.weight==b.weight)
        return a.speed>b.speed;
    return a.weight<b.weight;
}

int main(){
    int cn=0;
    int t1,t2;
    while(scanf("%d%d",&t1,&t2)!=EOF){
        ++cn;
        mice[cn].weight=t1;
        mice[cn].speed=t2;
        mice[cn].index=cn;
    }
    sort(mice+1,mice+1+cn,cmp);
    rep(i,1,cn){
        dp[i]=1;
        path[i]=i;
    }
    rep(i,2,cn){
        int temp=0;
        int tempPos=i;
        rep(j,1,i-1) if(mice[j].weight<mice[i].weight && mice[j].speed>mice[i].speed){
            if(dp[j]>temp){
                temp=dp[j];
                tempPos=j;
            }
        }
        dp[i]=temp+1;
        path[i]=tempPos;
    }
    int ans=-1;
    int ansPos=-1;
    rep(i,1,cn){
        if(dp[i]>ans){
            ans=dp[i];
            ansPos=i;
        }
    }
    printf("%d\n",ans);

    int cn2=0;
    while(path[ansPos]!=ansPos){
        finalPath[++cn2]=mice[ansPos].index;
        ansPos = path[ansPos];
    }
    printf("%d\n",mice[ansPos].index);
    rep2(i,cn2,1) printf("%d\n",finalPath[i]);


    return 0;
}