Les variables

Votre véhicule est équipé d'un réservoir contenant 20 litres d'essence, plein au démarrage.

Après une mesure précise, vous remarquez qu'en réalité votre véhicule consomme 2 litres à chaque mouvement.

Votre jauge étant toujours cassée, modifier l'algorithme suivant pour que la variable représente le niveau d'essence présent et diminue de 2 litres à chaque mouvement.

{"options": {"toolbox": [{"value_1": {"var_name": "essence", "type": "base_varvalue"}, "value_2": {"type": "base_numberinput", "value": 1.0}, "type": "base_simplecalculus", "op": "MINUS"}, {"type": "base_numberinput", "value": 1.0}, {"var_name": "essence", "type": "base_setvar"}], "blocks": {"base_start": {"inputs": [{"fields": [{"text": "Au d\u00e9marrage", "type": "text"}], "align": "left", "type": "dummy_input"}], "on_event": "start", "creatable": false, "tooltip": "D\u00e9marrage de l'algorithme", "colour": 65, "next_statement": true}, "base_numberinput": {"inputs": [{"fields": [{"default": 0.0, "type": "number_input", "name": "value"}], "align": "left", "type": "dummy_input"}], "colour": 260, "tooltip": "Fourni un nombre", "output": "Number"}, "road_forward": {"inputs": [{"fields": [{"text": "Avancer de 1 case", "type": "text"}], "align": "left", "type": "dummy_input"}], "colour": 160, "next_statement": true, "tooltip": "Avancer d'une case tout droit", "previous_statement": true}, "base_varvalue": {"inputs": [{"fields": [{"default": "x", "type": "variable", "name": "var_name"}], "align": "left", "type": "dummy_input"}], "colour": 330, "tooltip": "Fourni la valeur d'une variable", "output": true}, "base_simplerepeattimes": {"colour": 120, "tooltip": "Execute une suite d'instructions un certain nombre de fois", "previous_statement": true, "compound": {"blocks": {"base_repeattimes": {"inputs": [{"fields": [{"text": "R\u00e9p\u00e9ter", "type": "text"}], "align": "left", "type": "value_input", "name": "ntimes", "check": "Number"}, {"fields": [{"text": "fois", "type": "text"}], "align": "left", "type": "dummy_input"}, {"fields": [], "align": "left", "type": "statement_input", "name": "code_repeat", "check": null}], "colour": 120, "tooltip": "Execute une suite d'instructions un certain nombre de fois", "previous_statement": true, "inline": true, "next_statement": true}, "base_numberinput": {"inputs": [{"fields": [{"default": 0.0, "type": "number_input", "name": "value"}], "align": "left", "type": "dummy_input"}], "colour": 260, "tooltip": "Fourni un nombre", "output": "Number"}}, "ast": {"type": "base_repeattimes", "ntimes": {"alias": {"value": "ntimes"}, "type": "base_numberinput"}}}, "inline": true, "next_statement": true}, "base_setvar": {"inputs": [{"fields": [{"text": "mettre", "type": "text"}, {"default": "x", "type": "variable", "name": "var_name"}, {"text": "\u00e0", "type": "text"}], "align": "left", "type": "value_input", "name": "value", "check": null}], "colour": 330, "next_statement": true, "tooltip": "Affecter une valeur \u00e0 une variable", "previous_statement": true}, "base_simplecalculus": {"inputs": [{"fields": [], "align": "left", "type": "value_input", "name": "value_1", "check": "Number"}, {"fields": [{"type": "dropdown", "values": [["+", "PLUS"], ["-", "MINUS"], ["\u00d7", "TIMES"], ["\u00f7", "DIV"]], "name": "op"}], "align": "left", "type": "dummy_input"}, {"fields": [], "align": "left", "type": "value_input", "name": "value_2", "check": "Number"}], "colour": 260, "inline": true, "tooltip": "Effectue un calcul simple", "output": "Number"}}}, "ast": [[{"editable": false, "type": "base_start", "deletable": false}, {"code_repeat": [{"type": "road_forward", "deletable": false}], "type": "base_simplerepeattimes", "deletable": false, "ntimes": 5.0}]]}