link: http://codeforces.com/contest/330/problem/D
The discription looks so long, but the problem is simple if you can grasp the problem quickly.
1 /* 2 ID: zypz4571 3 LANG: C++ 4 TASK: 192d.cpp 5 */ 6 7 #include <iostream> 8 #include <cstdio> 9 #include <cstdlib> 10 #include <cstring> 11 #include <cmath> 12 #include <cctype> 13 #include <algorithm> 14 #include <queue> 15 #include <deque> 16 #include <queue> 17 #include <list> 18 #include <map> 19 #include <set> 20 #include <vector> 21 #include <utility> 22 #include <functional> 23 #include <fstream> 24 #include <iomanip> 25 #include <sstream> 26 #include <numeric> 27 #include <cassert> 28 #include <ctime> 29 30 #define INF 0x3f3f3f3f 31 #define REP(i, n) for(int i=0;i<int(n);++i) 32 #define FOR(i, a, b) for(int i=int(a);i<int(b);++i) 33 #define DWN(i, b, a) for(int i=int(b-1);i>=int(a);--i) 34 #define REP_1(i, n) for(int i=1;i<=int(n);++i) 35 #define mid int m=(l+r)/2 36 using namespace std; 37 int dir[4][2] = {{0,-1}, {0, 1}, {-1, 0}, {1, 0}}; 38 char mat[1003][1003]; 39 struct Node { 40 int x, y, time; 41 }; 42 Node start, end; 43 int ans, matime[1003][1003], n, m; 44 bool vis[1003][1003]; 45 void bfs(Node end) { 46 queue<Node> q; q.push(end); 47 while (!q.empty()) { 48 Node tmp; tmp = q.front(); q.pop(); 49 REP (i, 4) { 50 int x, y; 51 x = tmp.x + dir[i][0]; y = tmp.y + dir[i][1]; 52 if (x>=0 && x<n && y>=0 && y<m && mat[x][y] != 'T' && !vis[x][y]) { 53 Node t; t.x = x; t.y = y; t.time = tmp.time + 1; matime[x][y] = t.time; 54 q.push(t); vis[x][y] = true; 55 } 56 } 57 } 58 } 59 int main ( int argc, char *argv[] ) 60 { 61 #ifndef ONLINE_JUDGE 62 freopen("in.txt", "r", stdin); 63 #endif 64 cin>>n>>m; 65 memset(vis, false, sizeof(vis)); 66 REP (i, n) { 67 cin>>mat[i]; 68 REP (j, m) { 69 if (mat[i][j] == 'E') { 70 end.x = i, end.y = j; end.time = 0; 71 vis[i][j] = true; 72 matime[i][j] = 0; 73 } else if (mat[i][j] == 'S') { 74 start.x = i, start.y = j; 75 matime[i][j] = INF; 76 } else matime[i][j] = INF; 77 } 78 } 79 bfs(end); 80 int Time = matime[start.x][start.y], ans = 0; 81 REP (i, n) { 82 REP (j, m) { 83 if (isdigit(mat[i][j]) && matime[i][j] != INF) { 84 if (Time >= matime[i][j]) ans += (mat[i][j]-'0'); 85 } 86 } 87 } 88 printf("%d ", ans); 89 return EXIT_SUCCESS; 90 } /* ---------- end of function main ---------- */
standard dfs