1096. Consecutive Factors (20)解题报告

双重循环遍历2-sqrt（n）。遍历完，如果找不到因子，则此数为质数。

#define _CRT_SECURE_NO_WARNINGS#include <cstdio>#include <cstdlib>#include <cmath>#include <vector>using namespace std;int main(void) {int n, upper, i, j, tmpn;vector<int> consecfactor, tmp;scanf("%d", &n);upper = (int)sqrt(n) + 1;tmpn = n;for (i = 2; i < upper; i++) {for (j = i; j < upper; j++) {if (tmpn % j) {if (tmp.size() > consecfactor.size()) {consecfactor = tmp;}tmp.clear();tmpn = n;break;}else {tmp.push_back(j);tmpn /= j;}}}if (tmp.size() == 0 && consecfactor.size() == 0) {consecfactor.push_back(n);}else if (tmp.size() > consecfactor.size()) {consecfactor = tmp;}printf("%d\n%d", consecfactor.size(), consecfactor[0]);for (int i = 1; i < consecfactor.size(); i++) {printf("*%d", consecfactor[i]);}return 0;}