|
65 | 65 |
|
66 | 66 | <!-- 这里可写通用的实现逻辑 -->
|
67 | 67 |
|
| 68 | +**方法一:模拟** |
| 69 | + |
| 70 | +我们直接根据题目描述模拟即可,定义以下变量: |
| 71 | + |
| 72 | +- 变量 $mi$ 表示最小值; |
| 73 | +- 变量 $mx$ 表示最大值; |
| 74 | +- 变量 $s$ 表示总和; |
| 75 | +- 变量 $cnt$ 表示总个数; |
| 76 | +- 变量 $mode$ 表示众数。 |
| 77 | + |
| 78 | +我们遍历数组 $count$,对于当前遍历到的数字 $count[k]$,如果 $count[k] \gt 0$,那么我们做以下更新操作: |
| 79 | + |
| 80 | +- 更新 $mi = \min(mi, k)$; |
| 81 | +- 更新 $mx = \max(mx, k)$; |
| 82 | +- 更新 $s = s + k \times count[k]$; |
| 83 | +- 更新 $cnt = cnt + count[k]$; |
| 84 | +- 如果 $count[k] \gt count[mode]$,那么更新 $mode = k$。 |
| 85 | + |
| 86 | +遍历结束后,我们再根据 $cnt$ 的奇偶性来更新中位数 $median$,如果 $cnt$ 是奇数,那么中位数就是第 $\lfloor \frac{cnt}{2} \rfloor + 1$ 个数字,如果 $cnt$ 是偶数,那么中位数就是第 $\lfloor \frac{cnt}{2} \rfloor$ 和第 $\lfloor \frac{cnt}{2} \rfloor + 1$ 个数字的平均值。 |
| 87 | + |
| 88 | +最后,我们将 $mi, mx, \frac{s}{cnt}, median, mode$ 放入答案数组中返回即可。 |
| 89 | + |
| 90 | +时间复杂度 $O(n)$,其中 $n$ 是数组 $count$ 的长度。空间复杂度 $O(1)$。 |
| 91 | + |
68 | 92 | <!-- tabs:start -->
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69 | 93 |
|
70 | 94 | ### **Python3**
|
71 | 95 |
|
72 | 96 | <!-- 这里可写当前语言的特殊实现逻辑 -->
|
73 | 97 |
|
74 | 98 | ```python
|
| 99 | +class Solution: |
| 100 | + def sampleStats(self, count: List[int]) -> List[float]: |
| 101 | + def find(i: int) -> int: |
| 102 | + t = 0 |
| 103 | + for k, x in enumerate(count): |
| 104 | + t += x |
| 105 | + if t >= i: |
| 106 | + return k |
| 107 | + |
| 108 | + mi, mx = inf, -1 |
| 109 | + s = cnt = 0 |
| 110 | + mode = 0 |
| 111 | + for k, x in enumerate(count): |
| 112 | + if x: |
| 113 | + mi = min(mi, k) |
| 114 | + mx = max(mx, k) |
| 115 | + s += k * x |
| 116 | + cnt += x |
| 117 | + if x > count[mode]: |
| 118 | + mode = k |
75 | 119 |
|
| 120 | + median = ( |
| 121 | + find(cnt // 2 + 1) if cnt & 1 else (find(cnt // 2) + find(cnt // 2 + 1)) / 2 |
| 122 | + ) |
| 123 | + return [mi, mx, s / cnt, median, mode] |
76 | 124 | ```
|
77 | 125 |
|
78 | 126 | ### **Java**
|
79 | 127 |
|
80 | 128 | <!-- 这里可写当前语言的特殊实现逻辑 -->
|
81 | 129 |
|
82 | 130 | ```java
|
| 131 | +class Solution { |
| 132 | + private int[] count; |
| 133 | + |
| 134 | + public double[] sampleStats(int[] count) { |
| 135 | + this.count = count; |
| 136 | + int mi = 1 << 30, mx = -1; |
| 137 | + long s = 0; |
| 138 | + int cnt = 0; |
| 139 | + int mode = 0; |
| 140 | + for (int k = 0; k < count.length; ++k) { |
| 141 | + if (count[k] > 0) { |
| 142 | + mi = Math.min(mi, k); |
| 143 | + mx = Math.max(mx, k); |
| 144 | + s += 1L * k * count[k]; |
| 145 | + cnt += count[k]; |
| 146 | + if (count[k] > count[mode]) { |
| 147 | + mode = k; |
| 148 | + } |
| 149 | + } |
| 150 | + } |
| 151 | + double median = cnt % 2 == 1 ? find(cnt / 2 + 1) : (find(cnt / 2) + find(cnt / 2 + 1)) / 2.0; |
| 152 | + return new double[]{mi, mx, s * 1.0 / cnt, median, mode}; |
| 153 | + } |
| 154 | + |
| 155 | + private int find(int i) { |
| 156 | + for (int k = 0, t = 0;; ++k) { |
| 157 | + t += count[k]; |
| 158 | + if (t >= i) { |
| 159 | + return k; |
| 160 | + } |
| 161 | + } |
| 162 | + } |
| 163 | +} |
| 164 | +``` |
| 165 | + |
| 166 | +### **C++** |
| 167 | + |
| 168 | +```cpp |
| 169 | +class Solution { |
| 170 | +public: |
| 171 | + vector<double> sampleStats(vector<int>& count) { |
| 172 | + auto find = [&](int i) -> int { |
| 173 | + for (int k = 0, t = 0;; ++k) { |
| 174 | + t += count[k]; |
| 175 | + if (t >= i) { |
| 176 | + return k; |
| 177 | + } |
| 178 | + } |
| 179 | + }; |
| 180 | + int mi = 1 << 30, mx = -1; |
| 181 | + long long s = 0; |
| 182 | + int cnt = 0, mode = 0; |
| 183 | + for (int k = 0; k < count.size(); ++k) { |
| 184 | + if (count[k]) { |
| 185 | + mi = min(mi, k); |
| 186 | + mx = max(mx, k); |
| 187 | + s += 1LL * k * count[k]; |
| 188 | + cnt += count[k]; |
| 189 | + if (count[k] > count[mode]) { |
| 190 | + mode = k; |
| 191 | + } |
| 192 | + } |
| 193 | + } |
| 194 | + double median = cnt % 2 == 1 ? find(cnt / 2 + 1) : (find(cnt / 2) + find(cnt / 2 + 1)) / 2.0; |
| 195 | + return vector<double>{(double) mi, (double) mx, s * 1.0 / cnt, median, (double) mode}; |
| 196 | + } |
| 197 | +}; |
| 198 | +``` |
| 199 | +
|
| 200 | +### **Go** |
| 201 | +
|
| 202 | +```go |
| 203 | +func sampleStats(count []int) []float64 { |
| 204 | + find := func(i int) int { |
| 205 | + for k, t := 0, 0; ; k++ { |
| 206 | + t += count[k] |
| 207 | + if t >= i { |
| 208 | + return k |
| 209 | + } |
| 210 | + } |
| 211 | + } |
| 212 | + mi, mx := 1<<30, -1 |
| 213 | + s, cnt, mode := 0, 0, 0 |
| 214 | + for k, x := range count { |
| 215 | + if x > 0 { |
| 216 | + mi = min(mi, k) |
| 217 | + mx = max(mx, k) |
| 218 | + s += k * x |
| 219 | + cnt += x |
| 220 | + if x > count[mode] { |
| 221 | + mode = k |
| 222 | + } |
| 223 | + } |
| 224 | + } |
| 225 | + var median float64 |
| 226 | + if cnt&1 == 1 { |
| 227 | + median = float64(find(cnt/2 + 1)) |
| 228 | + } else { |
| 229 | + median = float64(find(cnt/2)+find(cnt/2+1)) / 2 |
| 230 | + } |
| 231 | + return []float64{float64(mi), float64(mx), float64(s) / float64(cnt), median, float64(mode)} |
| 232 | +} |
| 233 | +
|
| 234 | +func min(a, b int) int { |
| 235 | + if a < b { |
| 236 | + return a |
| 237 | + } |
| 238 | + return b |
| 239 | +} |
| 240 | +
|
| 241 | +func max(a, b int) int { |
| 242 | + if a > b { |
| 243 | + return a |
| 244 | + } |
| 245 | + return b |
| 246 | +} |
| 247 | +``` |
| 248 | + |
| 249 | +### **TypeScript** |
83 | 250 |
|
| 251 | +```ts |
| 252 | +function sampleStats(count: number[]): number[] { |
| 253 | + const find = (i: number): number => { |
| 254 | + for (let k = 0, t = 0; ; ++k) { |
| 255 | + t += count[k]; |
| 256 | + if (t >= i) { |
| 257 | + return k; |
| 258 | + } |
| 259 | + } |
| 260 | + } |
| 261 | + let mi = 1 << 30; |
| 262 | + let mx = -1; |
| 263 | + let [s, cnt, mode] = [0, 0, 0]; |
| 264 | + for (let k = 0; k < count.length; ++k) { |
| 265 | + if (count[k] > 0) { |
| 266 | + mi = Math.min(mi, k); |
| 267 | + mx = Math.max(mx, k); |
| 268 | + s += k * count[k]; |
| 269 | + cnt += count[k]; |
| 270 | + if (count[k] > count[mode]) { |
| 271 | + mode = k; |
| 272 | + } |
| 273 | + } |
| 274 | + } |
| 275 | + const median = cnt % 2 === 1 ? find((cnt >> 1) + 1) : (find(cnt >> 1) + find((cnt >> 1) + 1)) / 2; |
| 276 | + return [mi, mx, s / cnt, median, mode]; |
| 277 | +}; |
84 | 278 | ```
|
85 | 279 |
|
86 | 280 | ### **...**
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