Altered

Algorithm/Graph/DFS/UVa10603-Fill.cpp

@@ -0,0 +1,63 @@
+#include <iostream>
+#include <vector>
+#include <set>
+#include <bits/stdc++.h>
+using namespace std;
+
+bool have = false;
+set<tuple<int,int,int>> visited;
+
+int A, B, C; // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
+
+void dfs(int a, int b, int c, int target) {
+    if (a == target || b == target || c == target) {
+        have = true;
+        return;
+    }
+
+    auto state = make_tuple(a, b, c);
+    if (visited.find(state) != visited.end()) return;
+    visited.insert(state);
+
+    // <20><><EFBFBD>ֵ<EFBFBD>ˮ<EFBFBD><CBAE><EFBFBD><EFBFBD>
+    // a -> b
+    {
+        int pour = min(a, B - b);
+        dfs(a - pour, b + pour, c, target);
+    }
+    // a -> c
+    {
+        int pour = min(a, C - c);
+        dfs(a - pour, b, c + pour, target);
+    }
+    // b -> a
+    {
+        int pour = min(b, A - a);
+        dfs(a + pour, b - pour, c, target);
+    }
+    // b -> c
+    {
+        int pour = min(b, C - c);
+        dfs(a, b - pour, c + pour, target);
+    }
+    // c -> a
+    {
+        int pour = min(c, A - a);
+        dfs(a + pour, b, c - pour, target);
+    }
+    // c -> b
+    {
+        int pour = min(c, B - b);
+        dfs(a, b + pour, c - pour, target);
+    }
+}
+
+int main() {
+    int target;
+    cin >> A >> B >> C >> target;
+    dfs(A, 0, 0, target); // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC> A װ<><D7B0>
+    if (have) cout << "YES" << endl;
+    else cout << "NO" << endl;
+    return 0;
+}
+

Algorithm/Graph/DFS/UVa1600Knight-Move betteruseBSF.cpp

@@ -0,0 +1,32 @@
+#include <iostream>
+using namespace std;
+//ab<61><62><EFBFBD>յ<EFBFBD> 
+int dx[8] = {-2, -1, 1, 2, 2, 1, -1, -2};
+int dy[8] = {1, 2, 2, 1, -1, -2, -2, -1};
+int step[9][9];
+
+void dfs(int _a, int _b, int _n, int _m){
+	if(_n > 8 || _n < 1 || _m < 1 || _m > 8) return;
+	if(_n == _a && _m == _b) return;
+	for(int i = 0; i < 8; i++){
+		int nx = _n + dx[i];
+        int ny = _m + dy[i];
+        
+        if (nx >= 1 && nx <= 8 && ny >= 1 && ny <= 8) {
+            int stepnew = step[_n][_m] + 1;
+            if (step[nx][ny] == 0 || stepnew < step[nx][ny]) {
+                step[nx][ny] = stepnew;
+                dfs(_a, _b, nx, ny);
+            }
+        }
+	}
+}
+
+int main(){
+	int a, b, n, m;
+	cin >> n >> m >> a >> b;
+	step[n][m] = 0; 
+	dfs(a, b, n, m);
+	cout << step[a][b] << endl;
+	return 0;
+}

Algorithm/Graph/DFS/UVa572-Oil-Deposits.cpp

@@ -0,0 +1,51 @@
+#include <iostream>
+#include <vector>
+using namespace std;
+int m = 5, n = 5;
+vector<vector<char>> s;
+vector<vector<bool>> visited;
+vector<vector<int>> ids;
+
+	
+void dfs(int x, int y, int id){
+	if(x < 0 || x >= m || y < 0 || y >=n) return;
+	if(s[x][y] != '@') return;
+	if(visited[x][y] == true) return;
+	visited[x][y] = true; 
+	ids[x][y] = id;
+	dfs(x - 1, y - 1, id + 1);
+	dfs(x - 1, y, id + 1);
+	dfs(x - 1, y + 1, id + 1);
+	dfs(x, y - 1, id + 1);
+	dfs(x, y + 1, id + 1);
+	dfs(x + 1, y - 1, id + 1);
+	dfs(x + 1, y, id + 1);
+	dfs(x + 1, y + 1, id + 1);
+	cout << id << " ";
+}
+
+int main(){
+	s.resize(m);
+	visited.assign(m, vector<bool>(n, false));
+	ids.assign(m, vector<int>(n, 0));
+	char tmp;
+	for(int i = 0; i < m; i++){
+		for(int j = 0; j < n; j++){
+			cin >> tmp;
+			s[i].push_back(tmp);
+		}
+	}
+	for(int i = 0; i < m; i++){
+		for(int j = 0; j < n; j++){
+			if(!visited[i][j] && s[i][j] == '@') dfs(i, j, 1);
+		}
+	}
+	cout << endl;
+	int max = -1;
+	for(int i = 0; i < m; i++){
+		for(int j = 0; j < n; j++){
+			if(ids[i][j] > max) max = ids[i][j];
+		}
+	}
+	cout << max << endl;
+}

Algorithm/Graph/DFS/UVa673-Parentheses-Balance([]).cpp

@@ -0,0 +1,40 @@
+#include <iostream>
+#include <string>
+using namespace std;
+//确定每个节点要干什么
+bool dfs(const string& s, int l, int r) {
+    if (l > r) return true;           // 空串平衡
+    if (l == r) return false;         // 单个字符不平衡
+
+    // 必须匹配类型
+    char open = s[l];
+    char close = (open == '(') ? ')' : (open == '[') ? ']' : 0;
+    if (close == 0) return false;     // 非括号字符
+
+    int cnt = 0;
+    int p = -1;
+    for (int i = l; i <= r; i++) {
+        if (s[i] == '(' || s[i] == '[') cnt++;
+        if (s[i] == ')' || s[i] == ']') cnt--;
+        if (cnt == 0) {
+            p = i;                     // 找到匹配的右括号
+            break;
+        }
+    }
+
+    if (p == -1) return false;         // 没找到匹配
+    if (s[p] != close) return false;   // 类型不匹配(第一个和最后一个字符匹配)
+
+    // 内部和剩余区间递归
+    return dfs(s, l + 1, p - 1) && dfs(s, p + 1, r);
+}
+
+int main(){
+    string a;
+    while(true)
+    {
+        cin >> a;
+        dfs(a, 0, a.size() - 1) ? cout << "YES" << endl : cout << "NO" << endl;
+    }
+    return 0;
+}