|Vijos|图论最短路|P1406 古韵之鹊桥相会

来源：互联网发布：计算机二级vb上机题库编辑：程序博客网时间：2024/04/30 11:17

https://vijos.org/p/1406

两个相邻点相同则权值为0，否则权值为1.

不相邻点权值设为正无穷

然后在上面和下面加上一排数，上面的是起点，下面的是终点

最后Floyd，输出任意一个在起点和终点的距离(G[起点][终点])即可

#include<cstdio>#include<cstring>#include<algorithm>#include<queue>#include<vector>#define ms(i,j) memset(i, j, sizeof(i));#define pa2(a,r,c) for (int j=1;j<=c;j++) printf("%d  ", j);putchar('\n');for (int i=1;i<=r;i++) {for (int j=1;j<=c;j++) if (a[i][j]>4000000) printf("x  "); else printf("%d  ", a[i][j]); putchar('\n');}using namespace std;int n,m;int map[25][25];int G[2500][2500];int cnt = 0;void f(int i, int j, int c){if (j-1>0&&map[i][j-1]==map[i][j])G[c][c-1]=0;else if (j-1>0&&map[i][j-1]!=map[i][j])G[c][c-1]=1;if (j+1<=m&&map[i][j+1]==map[i][j])G[c][c+1]=0;else if (j+1<=m&&map[i][j+1]!=map[i][j])G[c][c+1]=1;if (i-1>0&&c-m>0&&map[i-1][j]==map[i][j])G[c][c-m]=0;else if (i-1>0&&c-m>0&&map[i-1][j]!=map[i][j])G[c][c-m]=1;if (i+1<=n&&map[i+1][j]==map[i][j])G[c][c+m]=0;else if (i+1<=n&&map[i+1][j]!=map[i][j])G[c][c+m]=1;}int main () { ms(G,27);scanf("%d%d%*c", &n,&m);for (int i=1;i<=n;i++){for (int j=1;j<=m;j++){map[i][j] = getchar();}getchar();}for (int i=1;i<=n;i++){for (int j=1;j<=m;j++){f(i,j, ++cnt);}}for (int i=cnt+1;i<=cnt+m;i++){G[i-m][i]=G[i][i-m]=0; if(i-1>cnt) G[i-1][i]=G[i][i-1]=0;} cnt += m;for (int i=cnt+1;i<=cnt+m;i++){G[i-cnt][i]=G[i][i-cnt]=0; if(i-1>cnt) G[i-1][i]=G[i][i-1]=0;} cnt += m;for (int k=1;k<=cnt;k++)for (int i=1;i<=cnt;i++)for (int j=1;j<=cnt;j++)if (k!=i&&k!=j&&i!=j){G[i][j] = min(G[i][j], G[i][k]+G[k][j]);}printf("%d\n", G[cnt][cnt-m-1]+1);return 0;}

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