CF 436(DIV.2)c

C. Bus
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

A bus moves along the coordinate line Ox from the point x = 0 to the point x = a. After starting from the point x = 0, it reaches the point x = a, immediately turns back and then moves to the point x = 0. After returning to the point x = 0 it immediately goes back to the point x = a and so on. Thus, the bus moves from x = 0 to x = a and back. Moving from the point x = 0 to x = a or from the point x = a to x = 0 is called a bus journey. In total, the bus must make k journeys.

The petrol tank of the bus can hold b liters of gasoline. To pass a single unit of distance the bus needs to spend exactly one liter of gasoline. The bus starts its first journey with a full petrol tank.

There is a gas station in point x = f. This point is between points x = 0 and x = a. There are no other gas stations on the bus route. While passing by a gas station in either direction the bus can stop and completely refuel its tank. Thus, after stopping to refuel the tank will contain b liters of gasoline.

What is the minimum number of times the bus needs to refuel at the point x = f to make k journeys? The first journey starts in the point x = 0.

Input

The first line contains four integers a, b, f, k (0 < f < a ≤ 106, 1 ≤ b ≤ 109, 1 ≤ k ≤ 104) — the endpoint of the first bus journey, the capacity of the fuel tank of the bus, the point where the gas station is located, and the required number of journeys.

Output

Print the minimum number of times the bus needs to refuel to make k journeys. If it is impossible for the bus to make k journeys, print -1.

Examples
Input
Copy
6 9 2 4
Output
Copy
4
Input
Copy
6 10 2 4
Output
Copy
2
Input
Copy
6 5 4 3
Output
Copy
-1

题意:

        给你一段路长度为a,要你走k次,在位置f有一个加油站,车一开始有b个单位的油,问你最少要加多少次油。

思路:

        很明显我们可以把车程分类,从左到右和从右到左,然后再分类,最后一次和不是最后一次,经过这2次分类,答案就很明显了。

code:

        

#include<stdio.h>
#include<iostream>
#include<string.h>
#include<string>
#include<algorithm>
#include<queue>
#include<functional>
typedef long long LL;
#define maxn 300005
using namespace std;
vector<int>arr[maxn];
LL n, a, b, k, f,flag,ans,d1,d2,mark,now;
int main()
{
	cin >> a >> b >> f >> k;
	d1 = f, d2 = a - f;
	mark = 1;
	now = b;
	while (k&&!flag)
	{
		if (mark%2)
		{
			if (now < d1)
			{
				flag = 1;
				break;
			}
			else
			{
				now -= d1;
				if (now < 2 * d2&&k!=1)
				{
					if (b < d2)
					{
						flag = 1;
						break;
					}
					else
					{
						now = b - d2;
						ans++;
					}
				}
				else if (k == 1)
				{
					if (now < d2)
					{
						if (b < d2)
						{
							flag = 1;
							break;
						}
						else
						{
							ans++;
						}
					}
				}
				else if (now >= d2*2)
				{
					now -= d2;
				}
			}
		}
		else
		{
			if (now < d2)
			{
				flag = 1;
				break;
			}
			else
			{
				now -= d2;
				if (now < d1 * 2 && k != 1)
				{
					if (b < d1)
					{
						flag = 1;
						break;
					}
					else
					{
						ans++;
						now = b - d1;
					}
				}
				else if (k == 1)
				{
					if (now < d1)
					{
						if (b < d1)
						{
							flag = 1;
							break;
						}
						else
						{
							ans++;
						}
					}
				}
				else if (now >= 2 * d1)
				{
					now -= d1;
				}
			}
		}
		mark++;
		k--;
	}
	if (!flag)
		cout << ans << endl;
	else
		cout << -1 << endl;
	return 0;
}

<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width,initial-scale=1.0"> <title>高德地图</title> <script src="https://gitee.com/dcloud/uni-app/raw/dev/dist/uni.webview.1.6.4.js"></script> <style> #map-container { width: 100%; height: 584px; border-radius: 22px; z-index: 4; } .amap-marker img { display: none; /* 隐藏默认图标 */ } </style> </head> <body> <div id="map-container"></div> <script> // 安全配置 window._AMapSecurityConfig = { securityJsCode: 'cf331d54f67e306ca5c0b17f7122d559' }; </script> <script src="https://webapi.amap.com/maps?v=2.0&key=f3323c24769b10828db07f07c0fcec0d&plugin=AMap.MarkerCluster"></script> <script> // 确保UniApp通信桥接准备就绪 function setupUniBridge() { return new Promise(resolve => { if (window.uni && typeof uni.postMessage === 'function') { return resolve(); } document.addEventListener('UniAppJSBridgeReady', resolve); }); } // 向UniApp发送消息 async function sendMessageToUniApp(data) { await setupUniBridge(); if (window.uni && typeof uni.postMessage === 'function') { uni.postMessage({ data: [JSON.stringify(data)] // 必须包装在数组中 }); } else if (window.parent) { window.parent.postMessage({ type: 'webviewMessage', data: JSON.stringify(data) }, '*'); } } // 解析URL参数 const params = new URLSearchParams(location.search); const points = JSON.parse(params.get('points') || '[]'); const markers = JSON.parse(params.get('markers') || '[]'); // 初始化地图 const map = new AMap.Map('map-container', { zoom: 10, center: points.length ? [points[0].lng, points[0].lat] : [116.397428, 39.90923], showBuildingBlock: true }); // 1. 绘制路线 if (points.length > 0) { const path = points.map(p => [p.lng, p.lat]); new AMap.Polyline({ path: path, strokeColor: "#32CD32", strokeWeight: 5, map: map }); // 添加起点终点标记 points.forEach((point, i) => { new AMap.Marker({ position: [point.lng, point.lat], offset: new AMap.Pixel(-10, -10), map: map }); }); } // 2. 初始化聚合点(使用官方推荐方式) let cluster; // 存储聚合实例 function initCluster() { // 转换数据格式为高德官方要求的格式 const clusterPoints = markers.map(marker => ({ lnglat: [marker.lng, marker.lat], // 注意属性名是lnglat title: marker.title, originalData: marker })); // 销毁旧实例(如果存在) if (cluster) { cluster.setMap(null); } // 创建聚合实例 cluster = new AMap.MarkerCluster(map, clusterPoints, { gridSize: 80, // 聚合网格像素大小 maxZoom: 18, // 最大聚合级别 minClusterSize: 2, // 最小聚合数量 // 自定义聚合点样式(官方推荐方式) renderClusterMarker: function(context) { const count = context.count; const div = document.createElement('div'); div.style.background = '#FF9A44'; div.style.borderRadius = '50%'; div.style.width = '40px'; div.style.height = '40px'; div.style.display = 'flex'; div.style.alignItems = 'center'; div.style.justifyContent = 'center'; div.style.color = 'white'; div.style.fontWeight = 'bold'; div.style.zIndex = '99'; div.innerHTML = count; return div; }, // 自定义非聚合点样式 renderMarker: function(context) { const markerData = context.data[0].originalData; const marker = new AMap.Marker({ position: [markerData.lng, markerData.lat], content: ` <div style="position:relative; text-align:center;z-index:100;"> <img src="https://a.amap.com/jsapi_demos/static/demo-center/icons/poi-marker-1.png" style="width:40px; height:50px; display:block;"> <div style="position:absolute; bottom:-90%; left:50%; transform:translateX(-50%); background: rgba(227, 57, 59, 0.1); padding:6px 0; border-radius: 18px; white-space:nowrap; font-size: 12px;font-weight: bold; margin-top:5px;border: 2px solid #F47C58;color:#E4393C;width:80px;"> ${markerData.title} </div> </div> `, offset: new AMap.Pixel(-20, -40) }); // 绑定点击事件 marker.on('click', async function(e) { await sendMessageToUniApp({ type: 'markerClick', data: markerData }); }); return marker; } }); // 绑定聚合点点击事件 cluster.on('click', async function(e) { await sendMessageToUniApp({ type: 'clusterClick', data: { count: e.clusterData.count, center: e.clusterData.center, markers: e.clusterData.markers } }); }); } // 3. 地图加载完成后初始化聚合点 map.on('complete', function() { if (markers.length > 0) { initCluster(); } }); </script> </body> </html> 聚合点还是默认图标,没有失效自定义样式
最新发布
08-08
<think>根据用户提供的信息,用户在高德地图的聚合点自定义样式时遇到了问题,特别是`renderClusterMarker`方法未生效。结合引用内容,我们分析可能的原因和解决方案。 ### 可能原因分析: 1. **版本兼容性问题**:高德地图JS API版本与MarkerCluster插件版本不兼容(引用[1]提到版本问题)。 2. **样式定义错误**:自定义样式时,DOM元素创建或样式设置不正确。 3. **地图未完全加载**:在`map.on('complete')`回调中初始化聚合点,但可能因异步问题导致聚合点未正确渲染。 4. **数据格式错误**:聚合点数据格式不符合要求,例如缺少`lnglat`属性或格式错误。 5. **插件未正确引入**:虽然代码中引入了`AMap.MarkerCluster`插件,但可能因为加载顺序问题导致插件未注册。 ### 解决方案: #### 1. 确保版本兼容性 - 使用相同版本的JS API和插件。检查`<script>`标签中JS API的版本与插件版本是否匹配。 - 建议使用最新稳定版本。 #### 2. 正确使用`renderClusterMarker` - 确保`renderClusterMarker`方法返回一个有效的DOM元素。 - 示例代码: ```javascript renderClusterMarker: function(context) { const count = context.count; const div = document.createElement('div'); div.style.cssText = ` background: #FF9A44; border-radius: 50%; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; color: white; font-weight: bold; z-index:99; `; div.innerHTML = count; return div; // 返回DOM元素 } ``` #### 3. 确保地图加载完成后再初始化聚合点 - 将聚合点初始化代码放在`map.on('complete', ...)`回调中。 ```javascript map.on('complete', function() { // 初始化聚合点 initCluster(); }); ``` #### 4. 检查数据格式 - 每个点必须包含`lnglat`属性,且为数组格式`[lng, lat]`。 ```javascript const clusterPoints = markers.map(marker => ({ lnglat: [marker.lng, marker.lat], // 正确格式 title: marker.title })); ``` #### 5. 确保插件正确加载 - 在JS API的`key`后添加`plugin=AMap.MarkerCluster`参数。 ```html <script src="https://webapi.amap.com/maps?v=2.0&key=您申请的key值&plugin=AMap.MarkerCluster"></script> ``` ### 完整示例代码(基于用户代码修改) ```html <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width,initial-scale=1.0"> <title>高德地图聚合点</title> <script src="https://gitee.com/dcloud/uni-app/raw/dev/dist/uni.webview.1.6.4.js"></script> <style> #map-container { width: 100%; height: 584px; border-radius: 22px; z-index: 4; } </style> </head> <body> <div id="map-container"></div> <script> window._AMapSecurityConfig = { securityJsCode: 'cf331d54f67e306ca5c0b17f7122d559' }; </script> <!-- 引入高德地图JS API,注意添加MarkerCluster插件 --> <script src="https://webapi.amap.com/maps?v=2.0&key=f3323c24769b10828db07f07c0fcec0d&plugin=AMap.MarkerCluster"></script> <script> // 解析URL参数 const params = new URLSearchParams(location.search); const points = JSON.parse(params.get('points') || '[]'); const markers = JSON.parse(params.get('markers') || '[]'); // 初始化地图 const map = new AMap.Map('map-container', { zoom: 10, center: points.length ? [points[0].lng, points[0].lat] : [116.397428, 39.90923], showBuildingBlock: true }); // 1. 绘制路线 if (points.length > 0) { const path = points.map(p => [p.lng, p.lat]); new AMap.Polyline({ path: path, strokeColor: "#32CD32", strokeWeight: 5, map: map }); } // 2. 初始化聚合点 function initCluster() { const clusterPoints = markers.map(marker => ({ lnglat: [marker.lng, marker.lat], // 确保lnglat格式正确 title: marker.title, originalData: marker })); // 创建聚合实例 const cluster = new AMap.MarkerCluster(map, clusterPoints, { gridSize: 80, maxZoom: 18, minClusterSize: 2, renderClusterMarker: function(context) { const count = context.count; const div = document.createElement('div'); div.style.cssText = ` background: #FF9A44; border-radius: 50%; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; color: white; font-weight: bold; z-index:99; `; div.innerHTML = count; return div; // 返回DOM元素 }, renderMarker: function(context) { const markerData = context.data[0].originalData; const marker = new AMap.Marker({ position: [markerData.lng, markerData.lat], content: ` <div style="position:relative; text-align:center;z-index:100;"> <img src="https://a.amap.com/jsapi_demos/static/demo-center/icons/poi-marker-1.png" style="width:40px; height:50px; display:block;"> <div style="position:absolute; bottom:-90%; left:50%; transform:translateX(-50%); background: rgba(227, 57, 59, 0.1); padding:6px 0; border-radius: 18px; white-space:nowrap; font-size: 12px;font-weight: bold; margin-top:5px;border: 2px solid #F47C58;color:#E4393C;width:80px;"> ${markerData.title} </div> </div> `, offset: new AMap.Pixel(-20, -40) }); return marker; } }); } // 3. 地图加载完成后初始化聚合点 map.on('complete', function() { if (markers.length > 0) { initCluster(); } }); </script> </body> </html> ``` ### 调试建议 1. 在浏览器中直接打开HTML文件,查看控制台是否有报错(如安全密钥错误、插件加载失败等)。 2. 检查网络请求,确保JS API和插件加载成功。 3. 使用简单数据测试,排除数据问题。 ### 引用说明 - 引用[1]提到版本兼容性问题,需检查JS API版本[^1]。 - 引用[2]提到自定义样式不生效,需注意地图加载完成后再初始化[^2]。 §§相关问题§§ 1. 高德地图JS API不同版本之间的主要差异有哪些? 2. 如何优化高德地图中海量点标记的渲染性能? 3. 高德地图的安全密钥(securityJsCode)如何配置?</think>### 高德地图 AMap.MarkerCluster 自定义聚合点样式不生效的原因及解决方案 根据高德地图官方文档和您的代码实现,自定义聚合点样式不生效(特别是 `renderClusterMarker` 未生效)通常由以下几个原因造成: #### 主要原因分析: 1. **插件加载顺序问题**(最常见)[^1][^2] - 必须在 `AMap.plugin('AMap.MarkerCluster')` 回调中创建聚合实例 - 错误示例:直接在全局作用域创建 `new AMap.MarkerCluster()` - 正确位置: ```javascript AMap.plugin('AMap.MarkerCluster', function() { // 这里创建聚合实例 }); ``` 2. **数据格式不符合要求**[^1] - 聚合点数据必须包含 `lnglat` 属性(数组格式) - 错误格式: ```javascript { lng: 106.123, lat: 38.456 } ``` - 正确格式: ```javascript { lnglat: [106.123, 38.456] } ``` 3. **地图未完全加载**[^2] - 聚合点必须在 `map.on('complete')` 事件后初始化 - 过早初始化会导致渲染失败 4. **自定义样式函数返回值错误** - `renderClusterMarker` 必须返回有效的 DOM 元素 - 常见错误:返回字符串而非 DOM 对象 #### 完整解决方案代码: ```html <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>高德地图聚合点修复版</title> <script> window._AMapSecurityConfig = { securityJsCode: 'cf331d54f67e306ca5c0b17f7122d559' }; </script> <script src="https://webapi.amap.com/maps?v=2.0&key=f3323c24769b10828db07f07c0fcec0d&plugin=AMap.MarkerCluster"></script> <style> #map-container { width: 100%; height: 584px; } </style> </head> <body> <div id="map-container"></div> <script> // 1. 解析URL参数 const params = new URLSearchParams(location.search); const points = JSON.parse(params.get('points') || '[]'); const markers = JSON.parse(params.get('markers') || '[]'); // 2. 初始化地图 const map = new AMap.Map('map-container', { zoom: 10, center: points.length ? [points[0].lng, points[0].lat] : [116.397428, 39.90923] }); // 3. 地图加载完成后初始化聚合点 map.on('complete', function() { // 关键:确保在插件加载回调中初始化 AMap.plugin('AMap.MarkerCluster', function() { // 转换数据格式(必须包含lnglat属性) const clusterPoints = markers.map(marker => ({ lnglat: [marker.lng, marker.lat], // 正确格式 title: marker.title, originalData: marker })); // 创建聚合实例(自定义样式) const cluster = new AMap.MarkerCluster(map, clusterPoints, { gridSize: 80, minClusterSize: 2, // 自定义聚合点样式 renderClusterMarker: function(context) { const div = document.createElement('div'); div.style.cssText = ` background: #FF9A44; border-radius: 50%; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; color: white; font-weight: bold; z-index:99; `; div.innerText = context.count; return div; // 返回DOM元素 }, // 自定义非聚合点样式 renderMarker: function(context) { const markerData = context.data[0].originalData; const marker = new AMap.Marker({ position: [markerData.lng, markerData.lat], content: ` <div style="position:relative; text-align:center;"> <img src="https://a.amap.com/jsapi_demos/static/demo-center/icons/poi-marker-1.png" style="width:40px; height:50px; display:block;"> <div style="position:absolute; bottom:-90%; left:50%; transform:translateX(-50%); background: rgba(227,57,59,0.1); padding:6px 0; border-radius: 18px; white-space:nowrap; font-size:12px; font-weight:bold; margin-top:5px; border:2px solid #F47C58; color:#E4393C; width:80px;"> ${markerData.title} </div> </div> `, offset: new AMap.Pixel(-20, -40) }); return marker; } }); }); }); </script> </body> </html> ``` #### 关键修复点说明: 1. **插件加载顺序**: ```javascript AMap.plugin('AMap.MarkerCluster', function() { // 聚合点初始化代码 }); ``` 2. **数据格式标准化**: ```javascript // 错误格式(导致渲染失败) { lng: 106.123, lat: 38.456 } // 正确格式(必须使用lnglat) { lnglat: [106.123, 38.456] } ``` 3. **DOM元素正确返回**: ```javascript renderClusterMarker: function(context) { const div = document.createElement('div'); // 创建DOM元素 // ...样式设置 return div; // 返回DOM对象而非字符串 } ``` 4. **地图加载事件**: ```javascript map.on('complete', function() { // 确保地图完成初始化 }); ``` #### 调试建议: 1. 在浏览器控制台检查是否有以下错误: - `AMap.MarkerCluster is not a constructor` → 插件未正确加载 - `Invalid lnglat object` → 数据格式错误 2. 使用最小测试数据集排除数据问题 3. 检查网络请求确保JS API加载成功(特别是安全密钥配置) > 根据高德官方文档,自定义聚合点必须在插件加载回调中创建,且数据格式必须符合 `{ lnglat: [lng, lat] }` 规范[^1]。同时建议使用最新版JS API(v2.0+)以避免兼容性问题[^2]。
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