/**
正解，最短路 */ #include <stdio.h> #include <string.h> #include <vector> #include <queue> #include <algorithm> using namespace std; #define N 1005 #define INF 1000000000LL #define MOD 1000000009LL struct node { int d,x,y; node(int a = 0,int b = 0,int c = 0) { x = a; y = b; d = c; } }; bool operator<(node a,node b) { return a.d > b.d; } #define MK node __int64 d[N][N],ds[N][N]; int n,mat[N][N]; bool vis[N][N]; node p,pt; int move[][2]= {0,1,1,0,0,-1,-1,0}; int ok(int x,int y) { return x >= 0 && x < n && y >= 0 && y < n && x >= y ; } void dij() { int i,j; for(i = 0; i < n; ++i) for(j = 0;j < n; ++j) d[i][j] = INF; memset(vis,0,sizeof(vis)); int x = n - 1, y = 0; d[x][y] = mat[x][y]; priority_queue< node > que; que.push(MK(x,y,d[x][y])); int dd; int px,py; while(!que.empty()) { p = que.top(); que.pop(); x = p.x; y = p.y; if(vis[x][y]) continue; vis[x][y] = 1; dd = p.d; for( i = 0; i < 4; ++i) { px = x + move[i][0]; py = y + move[i][1]; if(!ok(px,py)) continue; if(d[px][py] - dd> mat[px][py]) { d[px][py] = dd + mat[px][py]; que.push(MK(px,py,d[px][py])); } } } } int dfs(int x,int y) { if(ds[x][y]) return ds[x][y]; int res = 0,px,py; for(int i = 0; i < 4;++i) { px = x + move[i][0]; py = y + move[i][1]; if(!ok(px,py)) continue; if(d[px][py] + mat[x][y] == d[x][y]) res = (res + dfs(px,py)) % MOD; } return ds[x][y] = res; } int main() { // freopen("1.std.in","r",stdin); // freopen("1.out","w",stdout); int i,j; while(scanf("%d",&n) != EOF && n) { for(i = n - 1; i >= 0; --i) for(j = 0; j < n; ++j) scanf("%d",&mat[i][j]); for(i = n - 1; i > 0; --i) for(j = 0;j < i; ++j) mat[i][j] += mat[j][i]; dij(); __int64 minn = INF,sum = 0LL; for(i = 0; i < n; ++i) { if(d[i][i] < minn) minn = d[i][i]; } memset(ds,0,sizeof(ds)); ds[n-1][0] = 1; int x,y,k,cnt = 0; memset(vis,0,sizeof(vis)); ds[n-1][0] = 1; for(i = 0; i < n; ++i) if(ds[i][i] == 0) dfs(i,i); for(i = 0; i < n; ++i) if(d[i][i] == minn) sum = (sum + ds[i][i]) % MOD; printf("%I64d\n",sum); } return 0; } /** 开始很挫的一代码，priority_queue没弄好 比较，一直WA，还误觉得pair有问题。 */ #include <stdio.h> #include <string.h> #include <vector> #include <queue> #include <algorithm> using namespace std; #define N 505 #define INF 100000000 #define MOD 1000000009 #define MK make_pair //#define Pii pair<int,pair<int,int> > typedef pair<int,pair<int,int> > Pii; int d[N][N],ds[N][N]; int n,mat[N][N],vis[N][N]; Pii p,pt; int move[][2]= {0,1,1,0,0,-1,-1,0}; int ok(int x,int y) { return x >= 0 && x < n && y >= 0 && y < n && x >= y ; } void dij() { int i,j; for(i = 0; i < n; ++i) for(j = 0;j < n; ++j) d[i][j] = INF; memset(vis,0,sizeof(vis)); int x = n - 1, y = 0; d[x][y] = mat[x][y] + mat[y][x]; priority_queue<Pii,vector<Pii> ,greater<Pii> > que; que.push(MK(d[x][y],MK(x,y))); int dd; int px,py; while(!que.empty()) { p = que.top(); que.pop(); x = p.second.first; y = p.second.second; dd = p.first; // printf("..%d\n",dd); if(vis[x][y]) continue; vis[x][y] = 1; for( i = 0; i < 4; ++i) { px = x + move[i][0]; py = y + move[i][1]; if(!ok(px,py)) continue; if(px != py) { if(d[px][py] > dd + mat[px][py] + mat[py][px]) { d[px][py] = dd + mat[px][py] + mat[py][px]; que.push(MK(d[px][py],MK(px,py))); // printf("..=%d,%d,%d;%d\n",px,py,d[px][py],que.size()); } } else { if(d[px][py] > dd + mat[py][px]) { d[px][py] = dd + mat[py][px]; que.push(MK(d[px][py],MK(px,py))); // printf("..=%d,%d,%d;%d\n",px,py,d[px][py],que.size()); } } } } } Pii ss[N * N]; int main() { // freopen("1.std.in","r",stdin); // freopen("12.out","w",stdout); int i,j; while(scanf("%d",&n) != EOF && n) { for(i = n-1; i >= 0; --i) for(j = 0; j < n; ++j) scanf("%d",&mat[i][j]); dij(); int minn = INF,sum = 0; for(i = 0; i < n; ++i) { if(d[i][i] < minn) minn = d[i][i]; } memset(ds,0,sizeof(ds)); ds[n-1][0] = 1; int x,y,k,cnt = 0; priority_queue<Pii,vector<Pii> ,greater<Pii> > que; p = MK(d[n-1][0],MK(n-1,0)); que.push(p); memset(vis,0,sizeof(vis)); vis[n-1][0] = 1; while(!que.empty()) { p = que.top(); que.pop(); i = p.second.first; j = p.second.second; for(k = 0; k < 4; ++k) { x = i + move[k][0]; y = j + move[k][1]; //if(x == 0 && y == 0) if(!ok(x,y)) continue; if(x == y) { if(d[x][y] == d[i][j] + mat[x][y]) { ds[x][y] = (ds[i][j] + ds[x][y]) % MOD; if(!vis[x][y]) { que.push(MK(d[x][y],MK(x,y))); vis[x][y] = 1; } } } else { if(d[x][y] == d[i][j] + mat[x][y] + mat[y][x]) { ds[x][y] = (ds[i][j] + ds[x][y]) % MOD; if(!vis[x][y]) { que.push(MK(d[x][y],MK(x,y))); vis[x][y] = 1; } } } } } for(i = 0; i < n; ++i) if(d[i][i] == minn) sum = (sum + ds[i][i]) % MOD; printf("%d\n",sum); } return 0; } /** uva 12295 居然能够dp水过。 */ #include<stdio.h> #define N 101 #define MAX 1000000009 /* 对路径长度和数量同时DP， 策略是对角线向起终点两端扩展； */ int dp[N][N],n,pat[N][N]; int solve() { int i,j,k,f; for(i=0;i<n;++i) pat[i][i]=1; for(k=1;k<n;++k) for(i=k,j=0;i<n;++i,++j) { f=dp[i][j+1]-dp[i-1][j]; dp[i][j]+=dp[j][i]; if(f>0) { pat[i][j]=pat[i-1][j]; dp[i][j]+=dp[i-1][j]; } else if(f<0) { pat[i][j]=pat[i][j+1]; dp[i][j]+=dp[i][j+1]; } else { pat[i][j]=(pat[i][j+1]+pat[i-1][j])%MAX; dp[i][j]+=dp[i][j+1]; } } return pat[n-1][0]; } int main() { while(scanf("%d",&n)==1&&n) { int i,j; for(i=n-1;i>=0;--i) for(j=0;j<n;++j) scanf("%d",&dp[i][j]); printf("%d\n",solve()); } return 0; }