street lighting
topic description
N street lights are installed on a straight road,
starting from position 0, and the distance between street lights is fixed at 100 meters.
Each street light has its own lighting radius.
Please calculate the distance between the first street light and the last street light, which
cannot be illuminated . The length of the interval and .
enter description
The first line is a number N, indicating the number of street lights, 1 <= N <= 100000 The
second line is a number separated by N spaces, indicating the lighting radius of the street light, 1 <= lighting radius
output description
The sum of the lengths of the intervals that cannot be illuminated.
example one
enter
2
50 50
output
0
illustrate
Streetlight 1 covers 0-50 Streetlight 2 covers 50-100
Streetlight 1 and Streetlight 2 (0-100 meters) There is no uncovered section
Reference Problem Solving Java
import