[POJ2392]Space Elevator

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经典题

假如本题不按照高度排序肯定会错因为假如先放大的再放小的可能就放不进去了

不用你们说我也知道这个题有优化但是直接暴力枚举完全够做的了

/*One Night Of The Hunters*/#include<cstdio>#include<cstdlib>#include<iostream>#include<cstring>#include<algorithm>#include<queue>#include<iomanip>#include<stack>#include<map>#include<set>#include<cmath>#define debug(x) cerr<<#x<<"="<<x<<endl#define INF 0x7f7f7f7fusing namespace std;typedef pair<int,int> pii;int n;struct node{int h,a,c;}block[404];bool cmp(node x,node y){return x.a<y.a;}int f[4000001];int main(){scanf("%d",&n);for(int i=1;i<=n;i++){scanf("%d %d %d",&block[i].h,&block[i].a,&block[i].c);}int ans=0;sort(block+1,block+1+n,cmp);for(int i=1;i<=n;i++){for(int j=block[i].a;j>=block[i].h;j--){for(int k=0;k<=block[i].c;k++){if(j-k*block[i].h<0)break;f[j]=max(f[j],f[j-k*block[i].h]+k*block[i].h);ans=max(ans,f[j]);}}}printf("%d\n",ans);return 0;}/*srO xudyh davidlee1999WTK linkct1999 Orzcompiler TDM-GCC 5.9.2*/

二进制拆分

/*One Night Of The Hunters*/#include<cstdio>#include<cstdlib>#include<iostream>#include<cstring>#include<algorithm>#include<queue>#include<iomanip>#include<stack>#include<map>#include<set>#include<cmath>#define debug(x) cerr<<#x<<"="<<x<<endl#define INF 0x7f7f7f7fusing namespace std;typedef pair<int,int> pii;int n;struct node{int h,a,c;}block[404],stone[4444];bool cmp(node x,node y){return x.a<y.a;}int f[4000001];int main(){int cnt=0,k=1;scanf("%d",&n);for(int i=1;i<=n;i++){scanf("%d %d %d",&block[i].h,&block[i].a,&block[i].c);k=1;while(block[i].c-k>=0){stone[++cnt]=block[i];block[i].c-=k;stone[cnt].c=k;k*=2;}stone[++cnt]=block[i];}int ans=0;sort(stone+1,stone+1+cnt,cmp);for(int i=1;i<=cnt;i++){for(int j=stone[i].a;j>=stone[i].h*stone[i].c;j--){f[j]=max(f[j],f[j-(stone[i].h*stone[i].c)]+stone[i].h*stone[i].c);ans=max(ans,f[j]);}}printf("%d\n",ans);return 0;}/*srO xudyh davidlee1999WTK linkct1999 Orzcompiler TDM-GCC 5.9.2*/

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