URAL 1119 Metro

题目：click here

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF = 0x3f3f3f3f;
const int M = 1e3+3;

int n, m, k;
double dp[M][M];    // dp[i][j] 表示从[0,0]到[i,j]的最短距离
int mark[M][M];     // mark[i][j] 标记[i,j]与[i-1][j-1]之间有对角线
int main()  {
    while( ~scanf("%d%d%d", &n, &m, &k ) )  {
        memset( mark, 0, sizeof(mark) );
        for( int i=0; i<k; i++ )    {
            int x, y;   scanf("%d%d", &x, &y );
            mark[x][y] = 1;
        }
        dp[0][0] = 0;
        for( int i=1; i<=n; i++ )   dp[i][0] = dp[i-1][0] + 100;
        for( int j=1; j<=m; j++ )   dp[0][j] = dp[0][j-1] + 100;
        for( int i=1; i<=n; i++ )   {
            for( int j=1; j<=m; j++ )   {
                dp[i][j] = min( dp[i-1][j]+100, dp[i][j-1]+100 );
                if( mark[i][j] )
                    dp[i][j] = min( dp[i][j], dp[i-1][j-1]+141.421 );
            }
        }
        printf("%.0f\n", dp[n][m] );
    }
    return 0;
}