C语言有趣代码_c语言有趣代码大全

找1000内素数
 
Int main(){
 
 int a[1001] = {0};
 
 for(int I = 2;i<=1000;i++){
 
 if(a[i] == 0){
 
 printf("%d\n"ni);
 
 for(int j = i+I; j<=1000; j = j+i){
 
 a[j] = 1;
 
}}}
 
Return 0;
 
}
 
 
 
二分法找峰值
 
#include<stdio.h>
 
int feng(int* nums, int n) {
 
int left = 0;
 
int right = n - 1;
 
int mid;
 
while (left < right) {
 
mid = (left + right) / 2;
 
if (nums[mid] >= nums[mid + 1]) {
 
right = mid;
 
}
 
else {
 
left = mid + 1;
 
}
 
}
 
return left;
 
}
 
int main(){
 
int nums[7] = { 0 };
 
int n = sizeof(nums) / sizeof(int);
 
for (int i = 0; i < n ; i++) {
 
scanf("%d", &nums[i]);
 
}
 
int a;
 
a = feng(nums,n);
 
printf("%d",a );
 
return 0;
 
}
 
 
 
二分法找旋转数组最小值
 
 
 
#include<stdio.h>
 
int feng(int* nums, int n) {
 
int left = 0;
 
int right = n - 1;
 
int mid;
 
while (left < right) {
 
mid = (left + right) / 2;
 
if (nums[mid] > nums[right]) {
 
left = mid + 1;
 
}
 
else if(nums[mid] < nums[right]){
 
right = mid;
 
}
 
else {
 
right--;
 
}
 
}
 
return nums[left];
 
}
 
int main(){
 
int nums[5] = { 0 };
 
int n = sizeof(nums) / sizeof(int);
 
for (int i = 0; i < n ; i++) {
 
scanf("%d", &nums[i]);
 
}
 
int a;
 
a = feng(nums,n);
 
printf("%d",a );
 
return 0;
 
}
 
 
 
 
 
 
 
摩尔投票
 
 
 
int moertoupiao(int* nums,int n) {
 
int key = nums[0];
 
int count = 0;
 
for (int i = 0; i < n; i++) {
 
if (nums[i] == key) {
 
count++;
 
}
 
else {
 
count--;
 
}
 
if (count <= 0) {
 
key = nums[i + 1];
 
}
 
}
 
return key;
 
}
 
 
 
 
 
三色旗问题
 
#include<stdio.h>
 
void exchange(int* a, int* b) {
 
int c = *a;
 
*a = *b;
 
*b = c;
 
}
 
void paixu(int* arr,int a,int b) {
 
int index = 0;
 
int i = a - 1;
 
int j = b + 1;
 
int temp = 1;
 
while (index<j) {
 
if (arr[index]==temp) {
 
index++;
 
}
 
else if(arr[index]<temp){
 
exchange(&arr[++i],&arr[index]);
 
index++;
 
}
 
else if (arr[index]>temp) {
 
exchange(&arr[--j],&arr[index]);
 
}
 
}
 
}
 
int main() {
 
int arr[] = { 1,2,0,2,2,2,1,1,1,0,0,1,2,0,1,2,0,2,1,0,2,1,2,1 };
 
int n = sizeof(arr) / sizeof(int);
 
int i = 0;
 
    paixu(arr,i, n-1);
 
for (int i = 0; i < n; i++) {
 
printf("%d ", arr[i]);
 
}
 
return 0;
 
}