【实践课内】2.选择结构1

【实践课内】2.选择结构1/7-1 整数绝对值.c

@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+int main() {
+    int x;
+
+    scanf("%d", &x);
+
+    if (x < 0) {
+        printf("%d\n", -x);
+    } else {
+        printf("%d\n", x);
+    }
+
+    return 0;
+}

【实践课内】2.选择结构1/7-2 偶数乘2奇数乘3.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+
+int main() {
+    int x;
+
+    scanf("%d", &x);
+
+    if (x % 2 == 0) {
+        x *= 2;
+    } else {
+        x *= 3;
+    }
+
+    printf("y=%d\n", x);
+
+    return 0;
+}

【实践课内】2.选择结构1/7-3 成绩判定.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+
+int main() {
+    int x;
+
+    scanf("%d", &x);
+
+    if (60 <= x && x <= 100) {
+        printf("Pass\n");
+    } else if (0 <= x && x < 60) {
+        printf("No Pass\n");
+    } else {  // x < 0 || x > 100
+        printf("Data Error\n");
+    }
+
+    return 0;
+}

【实践课内】2.选择结构1/7-4 选择-计算器2.c

@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+int main() {
+    int a, b;
+    char op;
+
+    scanf("%d %c %d", &a, &op, &b);
+
+    if (op == '+') {
+        printf("%d\n", a + b);
+    } else if (op == '-') {
+        printf("%d\n", a - b);
+    } else if (op == '*') {
+        printf("%d\n", a * b);
+    } else if (op == '/' && b != 0) {
+        printf("%.2lf\n", (double)a / b);
+    } else if (op == '%' && b != 0) {
+        printf("%d\n", a % b);
+    } else {
+        printf("Error\n");
+    }
+
+    return 0;
+}

【实践课内】2.选择结构1/7-5 计算油费.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+
+const double P90 = 6.95;
+const double P93 = 7.44;
+const double P97 = 7.93;
+
+int main() {
+    int a, b;
+    char c;
+
+    scanf("%d %d %c", &a, &b, &c);
+
+    double ans = a;
+
+    if (b == 90) {
+        ans *= P90;
+    } else if (b == 93) {
+        ans *= P93;
+    } else {  // b == 97
+        ans *= P97;
+    }
+
+    if (c == 'm') {
+        ans *= 0.95;
+    } else {  // c == 'e'
+        ans *= 0.97;
+    }
+
+    printf("%.2lf\n", ans);
+
+    return 0;
+}