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
时间： 2024-09-27 04:29:00