Les variables

Votre véhicule est équipé d'un réservoir contenant 40 litres d'essence, plein au démarrage.

Votre jauge étant toujours cassée, vous vous rendez compte que votre moteur consomme de l'essence aussi lorsqu'il tourne. Modifier l'algorithme suivant pour que la variable représente le niveau d'essence présent sachant que votre véhicule consomme 2 litres lorsqu'il avance d'une case et 1 litre lorsqu'il tourne.

{"options": {"blocks": {"base_numberinput": {"output": "Number", "colour": 260, "tooltip": "Fourni un nombre", "inputs": [{"type": "dummy_input", "fields": [{"name": "value", "default": 0.0, "type": "number_input"}], "align": "left"}]}, "road_surroundingcaseroad": {"compound": {"blocks": {"road_surroundingcase": {"output": "Boolean", "colour": 210, "tooltip": "Test le type d'une case autour de la position courante", "inputs": [{"type": "dummy_input", "fields": [{"text": "la case", "type": "text"}, {"name": "dir", "values": [["en face", "front"], ["\u00e0 gauche", "left"], ["\u00e0 droite", "right"], ["derri\u00e8re", "back"]], "type": "dropdown"}, {"text": "est", "type": "text"}, {"name": "case_type", "values": [["une route", "road"], ["de l'herbe", "grass"]], "type": "dropdown"}], "align": "left"}], "inline": true}}, "ast": {"type": "road_surroundingcase", "case_type": "road"}}, "output": "Boolean", "colour": 210, "tooltip": "Test le type d'une case autour de la position courante est une route", "inline": true}, "base_start": {"next_statement": true, "colour": 65, "tooltip": "D\u00e9marrage de l'algorithme", "inputs": [{"type": "dummy_input", "fields": [{"text": "Au d\u00e9marrage", "type": "text"}], "align": "left"}], "creatable": false, "on_event": "start"}, "base_varvalue": {"output": true, "colour": 330, "tooltip": "Fourni la valeur d'une variable", "inputs": [{"type": "dummy_input", "fields": [{"name": "var_name", "default": "x", "type": "variable"}], "align": "left"}]}, "road_forward": {"previous_statement": true, "next_statement": true, "colour": 160, "tooltip": "Avancer d'une case tout droit", "inputs": [{"type": "dummy_input", "fields": [{"text": "Avancer de 1 case", "type": "text"}], "align": "left"}]}, "base_simplerepeattimes": {"compound": {"blocks": {"base_numberinput": {"output": "Number", "colour": 260, "tooltip": "Fourni un nombre", "inputs": [{"type": "dummy_input", "fields": [{"name": "value", "default": 0.0, "type": "number_input"}], "align": "left"}]}, "base_repeattimes": {"previous_statement": true, "next_statement": true, "colour": 120, "tooltip": "Execute une suite d'instructions un certain nombre de fois", "inputs": [{"type": "value_input", "fields": [{"text": "R\u00e9p\u00e9ter", "type": "text"}], "align": "left", "name": "ntimes", "check": "Number"}, {"type": "dummy_input", "fields": [{"text": "fois", "type": "text"}], "align": "left"}, {"type": "statement_input", "fields": [], "align": "left", "name": "code_repeat", "check": null}], "inline": true}}, "ast": {"type": "base_repeattimes", "ntimes": {"type": "base_numberinput", "alias": {"value": "ntimes"}}}}, "previous_statement": true, "next_statement": true, "colour": 120, "tooltip": "Execute une suite d'instructions un certain nombre de fois", "inline": true}, "base_setvar": {"previous_statement": true, "next_statement": true, "colour": 330, "tooltip": "Affecter une valeur \u00e0 une variable", "inputs": [{"type": "value_input", "fields": [{"text": "mettre", "type": "text"}, {"name": "var_name", "default": "x", "type": "variable"}, {"text": "\u00e0", "type": "text"}], "align": "left", "name": "value", "check": null}]}, "base_simplecalculus": {"output": "Number", "colour": 260, "tooltip": "Effectue un calcul simple", "inputs": [{"type": "value_input", "fields": [], "align": "left", "name": "value_1", "check": "Number"}, {"type": "dummy_input", "fields": [{"name": "op", "values": [["+", "PLUS"], ["-", "MINUS"], ["\u00d7", "TIMES"], ["\u00f7", "DIV"]], "type": "dropdown"}], "align": "left"}, {"type": "value_input", "fields": [], "align": "left", "name": "value_2", "check": "Number"}], "inline": true}, "base_if": {"previous_statement": true, "next_statement": true, "colour": 210, "tooltip": "Execute une suite d'instructions si une condition est v\u00e9rifi\u00e9", "inputs": [{"type": "value_input", "fields": [{"text": "Si", "type": "text"}], "align": "left", "name": "cond", "check": "Boolean"}, {"type": "statement_input", "fields": [], "align": "left", "name": "code_if", "check": null}]}, "road_turnleft": {"previous_statement": true, "next_statement": true, "colour": 160, "tooltip": "Tourner \u00e0 gauche", "inputs": [{"type": "dummy_input", "fields": [{"text": "Tourner \u00e0 gauche \u21b6", "type": "text"}], "align": "left"}]}}, "toolbox": [{"type": "base_simplecalculus", "value_1": {"type": "base_varvalue", "var_name": "essence"}, "value_2": {"type": "base_numberinput", "value": 1.0}, "op": "MINUS"}, {"type": "base_numberinput", "value": 1.0}, {"type": "base_setvar", "var_name": "essence"}]}, "ast": [[{"type": "base_start", "deletable": false, "editable": false}, {"type": "base_simplerepeattimes", "code_repeat": [{"type": "road_forward", "deletable": false}, {"type": "base_if", "cond": {"type": "road_surroundingcaseroad", "dir": "left", "deletable": false}, "code_if": [{"type": "road_turnleft", "deletable": false}], "deletable": false}], "ntimes": 18.0, "deletable": false}]]}