37 lines
733 B
C++
37 lines
733 B
C++
#include<stdio.h>
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int n,m,min;
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int ai[10],mi[10],used[10];
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int dfs(int dep,int hp)
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{
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int i;
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if(hp<=0)
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{
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if(dep-1<min) min=dep-1;
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return 0;
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}
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if(dep>=min) return 0;
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for(i=1;i<=n;i++)
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if(used[i]==0)
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{
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used[i]=1;
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if(hp<=mi[i])
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dfs(dep+1,hp-2*ai[i]);
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else
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dfs(dep+1,hp-ai[i]);
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used[i]=0;
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}
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}
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int main()
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{
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int i;
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while(scanf("%d%d",&n,&m)!=EOF)
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{
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for(i=1;i<=n;i++) scanf("%d%d",&ai[i],&mi[i]);
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for(i=1;i<=n;i++) used[i]=0;
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min=n+1;
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dfs(1,m);
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if(min==n+1) min=-1;
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printf("%d\n",min);
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}
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}
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