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Submission #521191

# Submission time Handle Problem Language Result Execution time Memory
521191 2022-02-01T07:56:13 Z zhangjishen Mecho (IOI09_mecho) C++
100 / 100
 188 ms 6268 KB 
#include<bits/stdc++.h>
using namespace std;

#define mp make_pair
#define pb push_back
#define fi first
#define se second
template<typename T> bool chkmin(T &a, T b){return b < a ? a = b, 1 : 0;}
template<typename T> bool chkmax(T &a, T b){return b > a ? a = b, 1 : 0;}
typedef pair<int, int> pii;
typedef long long ll;
const int MAXN = 810, inf = 1e9;
const int mv[4][2] = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};

int n, s, mx, my, dx, dy, d1[MAXN][MAXN], d2[MAXN][MAXN];
char g[MAXN][MAXN];

// bfs
bool valid(int x, int y){
	return x >= 1 && x <= n && y >= 1 && y <= n;
}

void bfs1(){
	queue<pii> q;
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= n; j++)
			if(g[i][j] == 'H')
				d1[i][j] = 0, q.push(mp(i, j));
			else d1[i][j] = inf;
	while(!q.empty()){
		pii u = q.front(); q.pop();
		for(int k = 0; k < 4; k++){
			int x = u.fi + mv[k][0];
			int y = u.se + mv[k][1];
			if(valid(x, y) && g[x][y] != 'T' && g[x][y] != 'D' && d1[x][y] == inf){
				d1[x][y] = d1[u.fi][u.se] + 1;
				q.push(mp(x, y));
			}
		}
	}
}

bool check(int t){
	queue<pii> q;
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= n; j++)
			d2[i][j] = inf;
	if(t < d1[mx][my])
		d2[mx][my] = 0, q.push(mp(mx, my));
	while(!q.empty()){
		pii u = q.front(); q.pop();
		for(int k = 0; k < 4; k++){
			int x = u.fi + mv[k][0];
			int y = u.se + mv[k][1];
			if(valid(x, y) && g[x][y] != 'T' && d2[x][y] == inf && (t + (d2[u.fi][u.se] + 1) / s < d1[x][y])){
				d2[x][y] = d2[u.fi][u.se] + 1;
				q.push(mp(x, y));
			}
		}
	}
	return d2[dx][dy] != inf;
}

int main(){
	// input
	scanf("%d %d", &n, &s);
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= n; j++){
			scanf(" %c", &g[i][j]);
			if(g[i][j] == 'M')
				mx = i, my = j;
			if(g[i][j] == 'D')
				dx = i, dy = j;
		}
	// prework(bfs)
	bfs1();
	// binary search
	int l = -1, r = n * n, mid;
	while(l < r){
		mid = (l + r + 1) / 2;
		if(check(mid))
			l = mid;
		else r = mid - 1;
	}
	printf("%d\n", l);
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:66:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |  scanf("%d %d", &n, &s);
      |  ~~~~~^~~~~~~~~~~~~~~~~
mecho.cpp:69:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |    scanf(" %c", &g[i][j]);
      |    ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 0 ms 332 KB Output is correct
5 Correct 0 ms 332 KB Output is correct
6 Correct 0 ms 332 KB Output is correct
7 Correct 94 ms 6008 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 0 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 0 ms 332 KB Output is correct
12 Correct 1 ms 716 KB Output is correct
13 Correct 1 ms 588 KB Output is correct
14 Correct 1 ms 716 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 0 ms 332 KB Output is correct
17 Correct 1 ms 460 KB Output is correct
18 Correct 1 ms 460 KB Output is correct
19 Correct 1 ms 460 KB Output is correct
20 Correct 0 ms 460 KB Output is correct
21 Correct 1 ms 588 KB Output is correct
22 Correct 1 ms 588 KB Output is correct
23 Correct 1 ms 588 KB Output is correct
24 Correct 1 ms 588 KB Output is correct
25 Correct 1 ms 716 KB Output is correct
26 Correct 1 ms 716 KB Output is correct
27 Correct 1 ms 716 KB Output is correct
28 Correct 1 ms 716 KB Output is correct
29 Correct 1 ms 716 KB Output is correct
30 Correct 1 ms 716 KB Output is correct
31 Correct 1 ms 844 KB Output is correct
32 Correct 1 ms 844 KB Output is correct
33 Correct 9 ms 2752 KB Output is correct
34 Correct 9 ms 2712 KB Output is correct
35 Correct 22 ms 2800 KB Output is correct
36 Correct 11 ms 3096 KB Output is correct
37 Correct 12 ms 3076 KB Output is correct
38 Correct 28 ms 3144 KB Output is correct
39 Correct 14 ms 3512 KB Output is correct
40 Correct 15 ms 3512 KB Output is correct
41 Correct 38 ms 3404 KB Output is correct
42 Correct 17 ms 3872 KB Output is correct
43 Correct 18 ms 3820 KB Output is correct
44 Correct 51 ms 3864 KB Output is correct
45 Correct 20 ms 4164 KB Output is correct
46 Correct 23 ms 4192 KB Output is correct
47 Correct 54 ms 4172 KB Output is correct
48 Correct 23 ms 4524 KB Output is correct
49 Correct 26 ms 4568 KB Output is correct
50 Correct 68 ms 4572 KB Output is correct
51 Correct 33 ms 4932 KB Output is correct
52 Correct 31 ms 4820 KB Output is correct
53 Correct 85 ms 4928 KB Output is correct
54 Correct 32 ms 5244 KB Output is correct
55 Correct 35 ms 5236 KB Output is correct
56 Correct 93 ms 5280 KB Output is correct
57 Correct 38 ms 5632 KB Output is correct
58 Correct 40 ms 5512 KB Output is correct
59 Correct 113 ms 5700 KB Output is correct
60 Correct 42 ms 5964 KB Output is correct
61 Correct 44 ms 5984 KB Output is correct
62 Correct 121 ms 6000 KB Output is correct
63 Correct 108 ms 5992 KB Output is correct
64 Correct 188 ms 5988 KB Output is correct
65 Correct 143 ms 6072 KB Output is correct
66 Correct 121 ms 5888 KB Output is correct
67 Correct 118 ms 5900 KB Output is correct
68 Correct 64 ms 6020 KB Output is correct
69 Correct 68 ms 6068 KB Output is correct
70 Correct 56 ms 5912 KB Output is correct
71 Correct 60 ms 6020 KB Output is correct
72 Correct 49 ms 5948 KB Output is correct
73 Correct 52 ms 6268 KB Output is correct
74 Correct 71 ms 6224 KB Output is correct
75 Correct 89 ms 6268 KB Output is correct
76 Correct 77 ms 6228 KB Output is correct
77 Correct 73 ms 6268 KB Output is correct
78 Correct 83 ms 6136 KB Output is correct
79 Correct 66 ms 6244 KB Output is correct
80 Correct 70 ms 6236 KB Output is correct
81 Correct 76 ms 6152 KB Output is correct
82 Correct 76 ms 6212 KB Output is correct
83 Correct 91 ms 6140 KB Output is correct
84 Correct 78 ms 6204 KB Output is correct
85 Correct 87 ms 6084 KB Output is correct
86 Correct 82 ms 6084 KB Output is correct
87 Correct 83 ms 6200 KB Output is correct
88 Correct 93 ms 6100 KB Output is correct
89 Correct 88 ms 6152 KB Output is correct
90 Correct 87 ms 6048 KB Output is correct
91 Correct 88 ms 6044 KB Output is correct
92 Correct 95 ms 6056 KB Output is correct