add solutions for problems

Author: tiny656

Data Structures and Algorithms (English)/7-1_Maximum Subsequence Sum (25).py

@@ -0,0 +1,19 @@
+n = int(input())
+arr = list(map(int, input().split()))
+
+max_val = max(arr)
+if max_val < 0:
+    print(0, arr[0], arr[-1])
+elif max_val == 0:
+    idx = arr.index(0)
+    print(0, arr[idx], arr[idx])
+else:
+    curr, ans, start, l, r = 0, 0, 0, 0, 0
+    for i, x in enumerate(arr):
+        curr += x
+        if curr > ans:
+            ans, l, r = curr, start, i
+        if curr < 0:
+            curr = 0
+            start = i + 1
+    print(ans, arr[l], arr[r])

Data Structures and Algorithms (English)/7-2_Reversing Linked List (25).cpp

@@ -0,0 +1,156 @@
+#define _CRT_SECURE_NO_DEPRECATE
+#define _SECURE_SCL 0
+#pragma comment(linker, "/STACK:66777216")
+#include <algorithm>
+#include <string>
+#include <complex>
+#include <cassert>
+#include <memory>
+#include <set>
+#include <stack>
+#include <map>
+#include <list>
+#include <deque>
+#include <numeric>
+#include <cctype>
+#include <cstddef>
+#include <vector>
+#include <queue>
+#include <iostream>
+#include <iomanip>
+#include <iterator>
+#include <cmath>
+#include <cstdio>
+#include <cstdlib>
+#include <sstream>
+#include <fstream>
+#include <ctime>
+#include <cstring>
+#include <functional>
+#include <bitset>
+using namespace std;
+
+#if defined(_MSC_VER) || defined(__BORLANDC__)
+typedef unsigned __int64 uint64;
+typedef signed __int64 int64;
+#else
+typedef unsigned long long uint64;
+typedef signed long long int64;
+#endif
+typedef vector<int> VI;
+typedef vector<string> VS;
+typedef pair<int, int> PII;
+typedef pair<int64, int64> PLL;
+typedef vector<int64> VL;
+
+#define pb push_back
+#define ppb pop_back
+#define mp make_pair
+#define fi first
+#define se second
+#define pii pair<int,int>
+#define pdd pair<double,double>
+#define FOR(i,a,b) for (int _n(b), i(a); i <= _n; i++)
+#define FORD(i,a,b) for(int i=(a),_b=(b);i>=_b;i--)
+#define all(c) (c).begin(), (c).end()
+#define SORT(c) sort(all(c))
+#define REP(i,n) FOR(i,1,(n))
+#define REPT(i,n) FOR(i,0,(n)-1)
+#define L(s) (int)((s).size())
+#define C(a) memset((a),0,sizeof(a))
+#define IOS ios::sync_with_stdio(false)
+
+const double pi = 3.1415926535897932384626433832795028841971;
+const double EPS = 1E-9;
+const int64 INF64 = ( int64 )1E18;
+const int INF = 1000000000;
+
+static inline bool get( int &v ) {
+	int s = 1, c;
+	while( !isdigit( c = getchar() ) && c != '-' )
+		if( c == EOF )    break ;
+	if( c == EOF ) return 0;
+	if( c == '-' ) s = 0 , v = 0;
+	else v = c ^ 48;
+	for( ; isdigit( c = getchar() ); v = ( v << 1 ) + ( v << 3 ) + ( c ^ 48 ) );
+	v = ( s ? v : -v );
+	return 1 ;
+}
+
+/*
+注意链表的起始地址可以从中间的节点开始，最后一个Test坑死了
+*/
+
+struct node_line
+{
+	int address, data, next;
+}tmp;
+
+pair<int, int> node[100099];
+
+vector< node_line > vList;
+void run() {
+	int start, n, k, i, j, prev, data, nxt;
+	cin >> start >> n >> k;
+	for (i = 0; i < n; i++) {
+		cin >> prev >> data >> nxt;
+		node[prev].first = data;
+		node[prev].second = nxt;
+	}
+	int cur_node = start;
+	while (cur_node != -1) {
+		tmp.address = cur_node;
+		tmp.data = node[cur_node].first;
+		tmp.next = node[cur_node].second;
+		cur_node = tmp.next;
+		vList.push_back(tmp);
+	}
+	int num = vList.size() / k;
+	for (i = 0; i < num; i++) {
+		for (j = (i+1)*k-1; j >= i*k; j--) {
+			printf("%05d %d ",vList[j].address, vList[j].data);
+
+			if (j == i*k) {
+				if (i < num-1) {
+					printf("%05d", vList[(i+2)*k-1].address);
+				} else {
+					if ((i+1)*k < vList.size()) {
+						printf("%05d", vList[(i+1)*k].address);
+					} else {
+						printf("-1");
+					}
+				}
+			} else {
+				printf("%05d", vList[j-1].address);
+			}
+			printf("\n");
+
+		}
+
+	}
+	if (vList.size() % k != 0) {
+		num = vList.size()%k;
+		for (i = vList.size()-num; i < vList.size(); i++) {
+			printf("%05d %d ", vList[i].address, vList[i].data);
+			if (i == vList.size()-1)	printf("-1\n");
+			else printf("%05d\n", vList[i+1].address);
+		}
+
+	}
+
+}
+
+
+int main() {
+#ifdef __DEBUG__
+	freopen( "test.in", "r", stdin );
+	freopen( "test.out", "w", stdout );
+	time_t st = clock();
+#endif
+	run();
+#ifdef __DEBUG__
+	printf( "\n=============\n" );
+	printf( "Time: %.2lf sec\n", ( clock() - st ) / double( CLOCKS_PER_SEC ) );
+#endif
+	return 0;
+}

Data Structures and Algorithms (English)/7-3_Pop Sequence (25).cpp

@@ -0,0 +1,38 @@
+#include <iostream>
+#include <cstring>
+#include <stack>
+using namespace std;
+
+int main()
+{
+	int m,n,k,cur,i,val;
+	scanf("%d %d %d", &m, &n, &k);
+	while(k--)
+	{
+		stack<int> s;
+		while(!s.empty()) s.pop();
+		s.push(1);
+		cur = 2;
+		int ok = 1;
+		for(i = 1; i <= n; i++)
+		{
+			scanf("%d", &val);
+			while( (s.empty() || val != s.top()) && (cur <= n) && ((int)s.size() < m) )
+			{
+				s.push(cur);
+				cur++;
+			}
+			if(val == s.top())
+			{
+				s.pop();
+			}
+			else
+			{
+				ok = 0;
+			}
+		}
+		if(!ok)	puts("NO");
+		else puts("YES");
+	}
+	return 0;
+}

Data Structures and Algorithms (English)/7-4_List Leaves (25).py

@@ -0,0 +1,23 @@
+n = int(input().strip())
+nodes = [tuple(int(x) if x != "-" else -1 for x in input().split()) for _ in range(n)]
+is_root = [True] * n
+for i, (l, r) in enumerate(nodes):
+    if l != -1:
+        is_root[l] = False
+    if r != -1:
+        is_root[r] = False
+
+root = is_root.index(True)
+leaves = []
+q = [root]
+while q:
+    u = q.pop(0)
+    l, r = nodes[u]
+    if l == r == -1:
+        leaves.append(u)
+    if l != -1:
+        q.append(l)
+    if r != -1:
+        q.append(r)
+
+print(*leaves)

Data Structures and Algorithms (English)/7-5_Tree Traversals Again (25).cpp

@@ -0,0 +1,77 @@
+#include <iostream>
+#include <algorithm>
+#include <queue>
+#include <cstdio>
+#include <cctype>
+#include <map>
+#include <string>
+#include <cstring>
+#include <stack>
+#include <set>
+using namespace std;
+
+class Command {
+public:
+	string op;
+	int val;
+}cmd_ins;
+
+class Node {
+public:
+	Node *left;
+	Node *right;
+	int val;
+} *root, *nodelist[40];
+
+vector<Command> cmdList;
+vector<int> postTravelArr;
+stack<int> st;
+
+void postTravel(Node *root) {
+	if (root->left != NULL)
+		postTravel(root->left);
+	if (root->right != NULL)
+		postTravel(root->right);
+	postTravelArr.push_back(root->val);
+}
+
+
+int main() {
+	int n;
+	cin >> n;
+	for (int i = 0; i < 2*n; i++) {
+		cin >> cmd_ins.op;
+		if (cmd_ins.op == "Push") {
+			cin >> cmd_ins.val;
+			st.push(cmd_ins.val);
+		} else {
+			cmd_ins.val = st.top();
+			st.pop();
+		}
+		cmdList.push_back(cmd_ins);
+		nodelist[cmd_ins.val] = new Node;
+		nodelist[cmd_ins.val]->left = NULL;
+		nodelist[cmd_ins.val]->right = NULL;
+		nodelist[cmd_ins.val]->val = cmd_ins.val;
+	}
+
+	root = nodelist[cmdList[0].val];
+
+	for (int i = 1; i < cmdList.size(); i++) {
+		// attach much attention to Push operation
+		// when two successive Push operation i-1 and i means Node i-1's left child is Node i
+		// when one operation is Pop, and another operation is Push, so operation i-1 Pop and i Push means, Node i-1's right child is Node i
+		if (cmdList[i].op == "Push") {
+			if (cmdList[i-1].op == "Push") nodelist[cmdList[i-1].val]->left = nodelist[cmdList[i].val];
+			else nodelist[cmdList[i-1].val]->right = nodelist[cmdList[i].val];
+		}
+	}
+
+	postTravel(root);
+	cout << postTravelArr[0];
+	for (int i = 1; i< postTravelArr.size(); i++) {
+		cout << " " << postTravelArr[i];
+	}
+	cout << endl;
+	return 0;
+}