整形_长整型的使用范围和规则

Posted 2020-09-28

整形_长整型的使用范围(两个数的乘积)

 

1.

I.unsigned long ：%lu ; unsigned long long ：%llu。

II.当结果在输出格式范围之内，则输出正确，否则不正确。

III. 当结果在输出格式范围之外，则输出的值与结果模(变量类型的大小的值)相等，且输出的值在变量类型的范围内。这里若结果大于2^64，则上述结论不正确。

 

Code：

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3  
 4 int main()
 5 {
 6     /**
 7 long   -2147483648～2147483647       2.1*10^9(2^31)
 8 unsigned long 0～4294967295          4.2*10^9(2^32)
 9 ( (unsigned) int 范围与 (unsigned) long 相同)
10 long long：-9223372036854775808～9223372036854775807      9.2*10^18(2^63)
11 unsigned long long：0～18446744073709551615               1.8*10^19(2^64)
12 ( (unsigned) __int64 范围与 (unsigned) long long 相同)
13     **/
14  
15     printf("%ld\n",2000000000);//<=2147483647,Y
16     ///3000000000 = -1294967296 (mod 2^32)
17     ///而 -1294967296 in [-2147483648,2147483647]
18     printf("%ld\n",3000000000);//>2147483647,N
19  
20     printf("%lu\n",4000000000);//<=4294967295,Y
21     ///5000000000 = 705032704 (mod 2^32)
22     ///而 705032704 in [0,4294967295]
23     printf("%lu\n",5000000000);//>4294967295,N
24  
25     printf("%lld\n",9000000000000000000);//<=9223372036854775807,Y
26     ///10000000000000000000 = -8446744073709551616 (mod 2^64)
27     ///而 -8446744073709551616 in [-9223372036854775808,9223372036854775807]
28     printf("%lld\n",10000000000000000000);//>9223372036854775807,N
29  
30     printf("%llu\n",18446744073709551615);//<=18446744073709551615,Y
31     ///18446744073709551616 <> 18446744069414584320 (mod 2^64)
32     ///超出整形范围(2^64)，则发生错误
33     printf("%llu\n",18446744073709551616);//>18446744073709551615,N
34     printf("%llu\n",18446744073709551617);//>18446744073709551615,N
35     printf("%llu\n",-1);//<-18446744073709551616,Y
36     printf("%llu\n",-2);//<-18446744073709551616,Y
37     ///mystery
38  
39     return 0;
40 }

 

 

 

 

2.

    ///1.一个整数在什么范围内，就默认为什么类型的数

    ///以下执行优先原则：

    ///I.在[-2^31,2^31-1]：long   II.在[0,2^32-1]：unsigned long

    ///III.在[-2^63,2^63-1]：long   IV.在[0,2^64-1]：unsigned long

    ///2.若计算式中的所有类型都小于输出的类型

    ///如计算式的类型是long/unsigned long , 输出的类型为long long/unsigned long long,

    ///，则输出结果错误！

    ///3.若计算式中存在数，数的类型大于输出的类型，

    ///而结果在输出的类型内，则输出结果正确！

    ///4.运算/输出需要什么类型，就必须转换为相对应的类型

    ///printf("%ld\n",(long)((double)2147483650*0.1));

 

Code：

  1 #include <stdio.h>
  2 #include <stdlib.h>
  3  
  4 int main()
  5 {
  6  
  7     ///1.一个整数在什么范围内，就默认为什么类型的数
  8     ///以下执行优先原则：
  9     ///I.在[-2^31,2^31-1]：long   II.在[0,2^32-1]：unsigned long
 10     ///III.在[-2^63,2^63-1]：long   IV.在[0,2^64-1]：unsigned long
 11     ///2.若计算式中的所有类型都小于输出的类型
 12     ///如计算式的类型是long/unsigned long , 输出的类型为long long/unsigned long long,
 13     ///，则输出结果错误！
 14     ///3.若计算式中存在数，数的类型大于输出的类型，
 15     ///而结果在输出的类型内，则输出结果正确！
 16     ///4.运算/输出需要什么类型，就必须转换为相对应的类型
 17     ///printf("%ld\n",(long)((double)2147483650*0.1));
 18  
 19  
 20     ///2
 21     ///long operation(+ - * /) long = long
 22     printf("%lld\n",1+1);
 23     printf("%lld\n",1-1);
 24     printf("%lld\n",1*1);
 25     printf("%lld\n",1/1);
 26  
 27     printf("\n");
 28  
 29     ///long operation (+ - * /) long = long long
 30     printf("%lld\n",2000000000+2000000000);
 31     printf("%lld\n",2000000000-(-2000000000));
 32     printf("%lld\n",2000000000*2000000000);
 33  
 34     printf("\n");
 35  
 36     ///unsigned long operation (+ - * /) unsigned long = long long
 37     printf("%lld\n",4000000000+4000000000);
 38     printf("%lld\n",4000000000-(-4000000000));
 39     printf("%lld\n",4000000000*(-4000000000));
 40  
 41     printf("\n");
 42  
 43     ///long operation (+ - * /) unsigned long = long long
 44     printf("%lld\n",2000000000+4000000000);
 45     printf("%lld\n",4000000000+2000000000);
 46     printf("%lld\n",2000000000-4000000000);
 47     printf("%lld\n",4000000000-2000000000);
 48     printf("%lld\n",2000000000*4000000000);
 49     printf("%lld\n",4000000000*2000000000);
 50  
 51     printf("\n");
 52  
 53     ///long operation (+ - * /) long long = long long
 54     printf("%lld\n",8000000000+2000000000);
 55     printf("%lld\n",2000000000+8000000000);
 56     printf("%lld\n",8000000000-2000000000);
 57     printf("%lld\n",2000000000-8000000000);
 58     printf("%lld\n",8000000000*1000000000);
 59     printf("%lld\n",1000000000*8000000000+1);
 60     printf("%lld\n",1+1000000000*8000000000);
 61  
 62     printf("\n");
 63  
 64     ///unsigned long operation (+ - * /) long long = long long
 65     printf("%lld\n",8000000000+4000000000);
 66     printf("%lld\n",4000000000+8000000000);
 67     printf("%lld\n",8000000000-4000000000);
 68     printf("%lld\n",4000000000-8000000000);
 69     ///乘会超界
 70  
 71     printf("\n");
 72  
 73     printf("\n--------------------------\n");
 74  
 75     ///long operation(+ - * /) long = long
 76     long a=1;
 77     printf("%lld\n",a+a);
 78     printf("%lld\n",a-a);
 79     printf("%lld\n",a*a);
 80     printf("%lld\n",a/a);
 81  
 82     printf("\n");
 83  
 84     ///long operation (+ - * /) long = long long
 85     long b=2000000000;
 86     printf("%lld\n",b+b);
 87     printf("%lld\n",b-(-b));
 88     printf("%lld\n",b*b);
 89  
 90     printf("\n");
 91  
 92     ///unsigned long operation (+ - * /) unsigned long = long long
 93     unsigned long c=4000000000;
 94     printf("%lld\n",c+c);
 95     printf("%lld\n",c-(-c));
 96     printf("%lld\n",c*(-c));
 97  
 98     printf("\n");
 99  
100     ///long operation (+ - * /) unsigned long = long long
101     printf("%lld\n",b+c);
102     printf("%lld\n",c+b);
103     printf("%lld\n",b-c);
104     printf("%lld\n",c-b);
105     printf("%lld\n",b*c);
106     printf("%lld\n",c*b);
107  
108     printf("\n");
109  
110     ///long operation (+ - * /) long long = long long
111     long long d=8000000000;
112     long e=1000000000;
113     printf("%lld\n",d+b);
114     printf("%lld\n",b+d);
115     printf("%lld\n",d-b);
116     printf("%lld\n",b-d);
117     printf("%lld\n",d*e);
118     printf("%lld\n",e*d+1);
119     printf("%lld\n",1+e*d);
120  
121     printf("\n");
122  
123     ///unsigned long operation (+ - * /) long long = long long
124     printf("%lld\n",d+c);
125     printf("%lld\n",c+d);
126     printf("%lld\n",d-c);
127     printf("%lld\n",c-d);
128     ///乘会超界
129  
130     printf("\n");
131  
132     printf("\n--------------------------\n");
133  
134     ///3
135     printf("%ld\n",6000000000+(-4000000000));
136     printf("%ld\n",100000000001-100000000000);
137  
138     printf("\n");
139  
140     printf("\n--------------------------\n");
141  
142     ///4
143     printf("%ld\n",5.5);
144  
145     printf("\n");
146  
147     printf("%ld\n",2147483650*0.1);
148     printf("%ld\n",2147483651*0.1);
149     printf("%ld\n",20*0.1);
150     printf("%ld\n",21*0.1);
151  
152     printf("\n");
153  
154     printf("%ld\n",(double)2147483650*0.1);
155     printf("%ld\n",(double)2147483651*0.1);
156     printf("%ld\n",(double)20*0.1);
157     printf("%ld\n",(double)21*0.1);
158  
159     printf("\n");
160  
161     printf("%ld\n",(long)((double)2147483650*0.1));
162     printf("%ld\n",(long)((double)2147483651*0.1));
163     printf("%ld\n",(long)((double)20*0.1));
164     printf("%ld\n",(long)((double)21*0.1));
165  
166  
167     printf("\n");
168  
169  
170  
171     return 0;
172 }
173