C++编写生成不重复的随机数代码
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vector<int> getRandom(int total){ srand((int)time(NULL)); std::vector<int> input = *new std::vector<int>(); for (int i = 0; i < total; i++) { input.push_back(i); } vector<int> output = *new vector<int>(); int end = total; for (int i = 0; i < total; i++) { vector<int>::iterator iter = input.begin(); int num = random()%end; iter = iter+num; output.push_back(*iter); input.erase(iter); end--; } return output;} |
再来一例：
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void permutation(int n, int *z_array){ int i, j, k, z; int buffer[N]; /* 初始化数组 */ for (i=0; i<n; i++) buffer[i]=0; /* 准备生成随机数,以当前时间为种子 */ srand((unsigned)time((long *)0)); /* 获得不重复的随机数据 */ for (i=0; i<n; i++) { /* 获得0~（n-i）的随机数据 */ z = rand()%(n-i); j=0; k=0; while (j<=z) { if (buffer[j+k]==0) j++; else k++; } buffer[j+k-1]=1; z_array[i]=j+k-1; } return;} |
方法三：来个复杂点的
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#include<stdio.h>#include <time.h>#include "iostream"#include <math.h>#define N 53using namespace std;//print arrayvoid display(int *a){ for (int i =0;i<N;i++) { cout<<" "<<a[i]<<" "; }}int main(void){ int b[N],a[N]; for (int i =0;i<N;i++) { b[i] = i+1; } // random(a); srand((unsigned)time(NULL)); int MaxIndex = N; for ( i= 0;i<N;i++) { // int index = (int)rand()%MaxIndex;//随机一个 0 - 52的index a[i] = b[index]; //随机到的数字给a[i],i from 0 to N-1 b[index] = b[MaxIndex-1]; MaxIndex--; } display(a); return 0;} |
以上3种方法均可实现生成不重复的随机数，具体的效率如何，小伙伴们自己测试下吧。
