mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
80 lines
1.7 KiB
C++
80 lines
1.7 KiB
C++
#include<iostream>
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using namespace std;
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#include<cstdio>
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#include<cstdlib>
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#include<cstring>
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#include<algorithm>
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#include<queue>
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#define N 51
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struct node{
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int x,y;
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node(int a,int b)
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{
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x=a; y=b;
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}
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node(){};
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};
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int key[4][2]={0,1,0,-1,1,0,-1,0};
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int n,map[N][N],d[N][N];
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long long f[N][N];
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void find()
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{
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int i;
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node s;
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queue<node> Q;
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memset(d,1,sizeof(d));
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d[n][n]=map[n][n];
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Q.push(node(n,n));
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while (!Q.empty())
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{
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s=Q.front();
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Q.pop();
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for (i=0;i<4;++i)
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{
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int x,y;
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x=s.x+key[i][0]; y=s.y+key[i][1];
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if (x>0&&x<=n && y>0&&y<=n)
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{
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if (d[x][y]>d[s.x][s.y]+map[x][y])
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{
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d[x][y]=d[s.x][s.y]+map[x][y];
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Q.push(node(x,y));
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}
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}
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}
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}
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}
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long long dp(int x,int y)
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{
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if (f[x][y]!=-1) return f[x][y];
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int i;
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long long t=0;
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for (i=0;i<4;++i)
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{
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int x1,y1;
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x1=x+key[i][0]; y1=y+key[i][1];
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if (x1>0&&x1<=n && y1>0&&y1<=n)
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if (d[x1][y1]<d[x][y])
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{
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t+=dp(x1,y1);
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}
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}
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return f[x][y]=t;
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}
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int main()
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{
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while (~scanf("%d",&n))
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{
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int i,j;
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for (i=1;i<=n;++i)
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for (j=1;j<=n;++j)
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scanf("%d",&map[i][j]);
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find();
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memset(f,-1,sizeof(f));
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f[n][n]=1;
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dp(1,1);
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printf("%I64d\n",f[1][1]);
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}
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return 0;
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}
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