长理算法复习

选择排序

#include<iostream>using namespace std;const int N = 1010;
int a[N];
int n;void selectSort(){for (int i = 0; i < n;i++){int pos = i;for (int j = i + 1; j < n;j++){if(a[j]<a[pos])pos = j;}swap(a[i], a[pos]);}
}int main()
{cin >> n;for (int i = 0; i < n;i++){cin >> a[i];}selectSort();for (int i = 0; i < n;i++){cout << a[i] << " ";}return 0;
}

蜜蜂路线

#include <cstdio>
int main(){long long f[105];f[1]=1;f[2]=2;for(int i=3;i<=100;i++) f[i]=f[i-1]+f[i-2];int n;int a,b;scanf("%d%d",&a,&b);printf("%lld\n",f[b-a]);return 0;
}

读写文件

#include<stdio.h>
#include<stdlib.h>int cmp(const void *a, const void *b)
{const int *pa = a, *pb = b;return *pb - *pa; // 逆序比较
}
int main(){const char *filename = "original.txt";//打开文件读取数据//打开文件FILE *fin;if((fin=fopen(filename,"r"))==NULL){perror(filename);return 1;//读取文件失败}//读取数据int a[1024];int n = 0;while ((fscanf(fin,"%d",&a[n])==1)){n++;}//关闭文件fclose(fin);//数据排序qsort(a, n, sizeof(int), cmp);//写入文件//打开文件FILE *fout;if ((fout = fopen(filename, "w")) == NULL){perror(filename);return 2; // 写文件失败}//写入数据for (int i = 0; i < n; i++)fprintf(fout, "%d\n", a[i]);//关闭文件fclose(fout);return 0;
}