C语言经典弱智问题解法整理

<1>交换

//1)输入输出
#include<stdio.h>
int main(void){
	int a, b;
	scanf("%d %d", &a, &b);
	printf("%d %d\n", b, a);
	return 0;
}

//2)第三变量
#include<stdio.h>
int main(void){
	int a, b, t;
	scanf("%d %d", &a, &b);
	t = a; a = b; b = t;
	printf("%d %d\n", a, b);
	return 0;
}

//3)加减法
#include<stdio.h>
int main(void){
	int a, b;
	scanf("%d %d", &a, &b);
	a = a + b;
	b = a - b;
	a = a - b;
	printf("%d %d\n", a, b);
	return 0;
}

//4)乘除法
#include<stdio.h>
int main(void){
	int a, b;
	scanf("%d %d", &a, &b);
	a = a*b;
	b = a/b;
	a = a/b;
	printf("%d %d\n", a, b);
	return 0;
}

//5)异或运算
#include<stdio.h>
int main(void){
	int a, b;
	scanf("%d %d", &a, &b);
	a ^= b ^= a ^= b;
	printf("%d %d\n", a, b);
	return 0;
}

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

<2>两数相加

//1)加法运算
#include<stdio.h>
int main(){
	int a, b;
	scanf("%d %d",&a, &b);
	printf("%d\n",a+b);
	return 0;
}

//2)逻辑运算
#include <stdio.h>
int add(int a ,int b){
	if(a==0) return b;
	return add((a&b)<<1, (a^b));
}  
int main(){
    int a ,b;
    scanf("%d %d",&a,&b);
    printf("%d\n", add(a,b));
    return 0;
}

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

<3>待更新

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------